Research ArticleDifferent Spectrophotometric Methods for SimultaneousDetermination of Trelagliptin and Its Acid Degradation Product

Shereen Mowaka 123 Bassam M Ayoub 23 Mostafa A Hassan234 andWafaa A Zaghary4

1Analytical Chemistry Department Faculty of Pharmacy Helwan University Ein Helwan Cairo 11795 Egypt2Pharmaceutical Chemistry Department Faculty of Pharmacy e British University in Egypt El-Shorouk CityCairo 11837 Egypt3e Center for Drug Research and Development (CDRD) Faculty of Pharmacye British University in Egypt El-Shorouk CityCairo 11837 Egypt4Pharmaceutical Chemistry Department Faculty of Pharmacy Helwan University Ein Helwan Cairo 11795 Egypt

Correspondence should be addressed to Bassam M Ayoub bassamayoubbueedueg

Received 5 July 2017 Accepted 3 December 2017 Published 30 January 2018

Academic Editor Krishna K Verma

Copyright copy 2018 ShereenMowaka et al-is is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

New spectrophotometric and chemometric methods were carried out for the simultaneous assay of trelagliptin (TRG) and its aciddegradation product (TAD) and applied successfully as a stability indicating assay to recently approved Zafatekreg tablets TAD wasmonitored using TLC to ensure complete degradation Furthermore HPLC was used to confirm dealing with one major aciddegradation product -e proposed methods were developed by manipulating zero-order first-derivative and ratio spectra ofTRG and TAD using simultaneous equation first-derivative and mean-centering methods respectively Using Spectra ManagerII andMinitab v14 software the absorbance at 274 nmndash2604 nm amplitudes at 2604 nmndash2740 nm and mean-centered values at2876 nmndash2572 nmwere measured against methanol as a blank for TRG and TAD respectively Linearity and the other validationparameters were acceptable at concentration ranges of 5ndash50 μgmL and 25ndash25 μgmL for TRG and TAD respectively Using one-way analysis of variance (ANOVA) the optimized methods were compared and proved to be accurate for the simultaneous assayof TRG and TAD

1 Introduction

Trelagliptin (TRG) (Figure 1) is a dipeptidyl peptidase-4 (DPP-4) inhibitor for treating type 2 diabetes mellitus as a once-weekly monotherapy Its mechanism of action includesinhibiting the DPP-4 enzyme that leads to increment ofglucagon-like peptide-1 (GLP-1) and other hormone levels [1]TRG administration once weekly showed a high efficacy andgood safety profile [2 3] TRG kinetic analysis revealed re-versible and slow-binding inhibition of DPP-4 while X-raydiffraction data indicated a noncovalent interaction betweenDPP-4 and TRG [4 5] DPP-4 inhibitors are weight neutraland well tolerated and provide better glycaemic control fora longer period compared to conventional therapies Despitethe fact that various drugs are available glycaemic control

remains suboptimal in approximately half of patients with type2 diabetes mellitus one of the major reasons for low medi-cation adherence [6ndash8] A novel DPP-4 inhibitor TRG wasapproved in Japan in March 2015 and is the first once-weeklyoral antidiabetic agent in the world Medication adherence forthe treatment of diabetes was reviewed in the recent phases III and III clinical studies TRG has demonstrated superiorityto placebo and noninferiority to alogliptin indicating its ef-ficacy and tolerance in Japanese patients TRG is expected toimprove adherence and prevent complications Due to theconvenient dosing regimen it is expected to be widely used inthe clinical setting [6ndash9]

Although some LC methods were reported for quanti-fication of TRG [10ndash12] no methods were found in theliterature dealing with the direct UV assay of TRG in its

HindawiJournal of Analytical Methods in ChemistryVolume 2018 Article ID 7370651 7 pageshttpsdoiorg10115520187370651

pharmaceutical dosage form In addition no methods wereused for the simultaneous assay of TRG and its acid deg-radation product (TAD) using UV spectrophotometrictechniques TAD (Figure 1) was found in the literature tobe the main acid degradation product [12 13] which is2-[(3-methyl-2 4 6-oxo-tetrahydro-pyrimidin-1(2H) yl)-methyl]-4-fluorobenzonitrile Literature results were ascer-tained by separating TRG from its acid degradation producton the TLC that results in two separated spots before thecomplete degradation and showed only one spot after fi-nalizing the stress conditions as reported [12 13] Moreoverin this presented work HPLC-UV was used to confirm thatwe have one major degradation product where chromato-graphic separation of TRG from TAD was obtained withretention times for TRG and its acid degradation productequal to 186 and 243 respectively (Figure 1)

-e present work is considered as the first spectropho-tometric methods for the analysis of TRG in Zafatekreg tabletsand for simultaneous determination of TRG in the presence ofTAD that are considered as simple and inexpensive techniques-is study presents different methods resolving the overlappedspectra of TRG and TAD by manipulating their zero-orderfirst-order and ratio spectra using simultaneous equationfirst-derivative and mean-centering methods respectively

2 Experimental

21 Instruments UV spectrophotometer (SN C367961148Japan JASCO) was used

22 Reagents Reference Samples and Stock and WorkingSolutions TRG was certified to contain more than 990and Zafatek tablets (each tablet contains 50mg of TRG) wereprovided by Takeda Pharmaceuticals Ltd (Japan) Stocksolutions (1mgmL) and their appropriate dilution toworking solutions (100 microgmL) of TRG were preparedseparately in analytical grade methanol purchased fromSigma-Aldrich (Germany)

23 Sample Preparation -e coats of twenty Zafatek tabletswere carefully removed then the tablets were powdered andmixed An accurately weighed amount equivalent to 10mgof TRG was transferred to a 100mL volumetric flaskcompleted to volume with methanol sonicated to dissolveand filtered Two three and four milliliters of the previouslyprepared extract were added separately to a series of 10mLvolumetric flasks and completed to volume with methanol-e final TRG concentrations were equivalent to 20 30 and40 microgmL

24 Preparation of the Trelagliptin Acid Degradation Product(TAD) Using TRG stock solution (1mgmL) acidic hy-drolysis of TRG was carried out in a Fischer brand dis-posable tube by mixing 25mL of TRG stock solution with25mL of 1 N HCl and was heated for 2 hours at 90degC At thespecified time (after cooling the tube contents) a precalcu-lated amount of 1 N NaOH was added to neutralize the tubecontents-en the tube contents were transferred into a 50mLvolumetric flask and completed to volume with methanol-us the concentration of TAD was assumed to be 50μgmLComplete acidic hydrolysis of TRG was confirmed by injectingthe sample into the HPLC-UV system that results in only onepeak with a retention time of 243 (instead of TRG retentiontime that equals 186) Also the sample was separated on TLCthat results in only one spot that is corresponding to TAD-esample was stored under 4degC until analysis

25 Procedure

251 Preliminary Investigation -e zero-order absorptionspectra of TRG (30 microgmL) and TAD (15 microgmL) wererecorded separately against methanol as a blank Overlay ofboth TRG and TAD spectra (Figure 2(a)) showed themaximum absorption (λmax) at 274 nm and 2604 nm re-spectively Overlay of the first-order spectra of TRG(30 microgmL) and TAD (15 microgmL) showed the TAD zerocrossing point at 2604 nm and the TRG zero crossing pointat 2740 nm as shown in Figure 2(b)

252 Linearity Aliquots of working solutions corre-sponding to 50ndash500microgmL and 25ndash250microgmL of TRG andTAD respectively were added separately into a series of 10mLvolumetric flasks and completed to volume withmethanol-ecorresponding absorbance was measured at 2740 nm and2604 nm for TRG and TAD respectively using methanol asa blank Calibration curves (absorbance against concentration)were constructed for both TRG and TAD

250240

220

200

180

160

140

120

100

80

60

40

20

0

-20

-40-50

Abs

orba

nce

(mAU

)

000 050 100 150 200 250 272Time (min)

N

N

N

N

N

OF

O

ON

FN OO

H2N

(b)

(a)

Figure 1 HPLC-UV chromatogram of laboratory-preparedmixture containing concentrations equivalent to 45 microgmL and9 microgmL of TRG (a) and TAD (b) respectively

2 Journal of Analytical Methods in Chemistry

26 Simultaneous Equation Method -e simultaneousequation spectrophotometric method was successfully ap-plied to TRG and TAD by manipulating their zero-orderabsorption spectra TRG and TAD showed the maximumabsorption (λmax) at 274 nm (λmax 1) and 2604 nm (λmax 2)respectively Absorbance at λmax 1 and λmax 2 was plottedagainst the corresponding concentrations of TRG and TADrespectively and calibration curves were constructedMixtures of TRG and TAD with different lambdas andconcentrations of TRG and TAD (CTRG and CTAD) can becalculated by a simultaneous equation -rough absorbanceof the sample at λ1 and λ2 (A1 and A2) absorptivities ofTRG at λmax 1 and λmax 2 (aTRG 1 and aTRG 2) and ab-sorptivities of TAD at λmax 1 and λmax 2 (aTAD 1 and aTAD 2)are as follows

CTRG A2lowast aTAD 1( 1113857minus A1lowast aTAD 2( 11138571113858 1113859

aTRG 2lowast aTAD 1( 1113857minus aTRG 1lowast aTAD 2( 11138571113858 1113859

CTAD A1lowast aTRG 2( 1113857minus A2lowast aTRG 1( 11138571113858 1113859

aTRG 2lowast aTAD 1( 1113857minus aTRG 1lowast aTAD 2( 11138571113858 1113859

(1)

-e total absorbance is the sum of TRG and TAD ab-sorbance as their λmax are relatively dissimilar and they donot interact chemically

27 First-Derivative Method -e first-derivative spectro-photometric method was successfully applied to TRG andTAD by manipulating their first-order spectra -e ampli-tudes of the first-order spectra were measured for TRG andTAD at 2604 nm and 274 nm respectively -en the am-plitudes were plotted against corresponding concentrationsof TRG and TAD to construct calibration curves

28 Mean-Centering Method -e scanned zero-orderspectra of TRG and TAD were separately divided by25 microgmL of TAD and 50 microgmL of TRG respectivelyUsing the Minitab v14 program the obtained ratio spectrawere mean centered and then the mean-centered values of

TRG and TAD were measured at 2876 nm and 2572 nmrespectively Calibration curves were constructed byplotting the mean-centered values against correspondingconcentrations

281 Accuracy and Precision -ree different ratios of thedrug and its degradation product (TAD equals to 10 15and 20 of TRG) as 3 laboratory-prepared mixtures wereapplied using concentrations corresponding to 35 40 and45 microgmL and 35 6 and 9 microgmL of TRG and TAD re-spectively-e zero-order absorption spectra of the mixtureswere recorded using methanol as a blank Finally the ob-tained spectra were manipulated by different methods tocalculate the corresponding concentration of each drugFurthermore they were analyzed using the proposedmethods three times within the same day (n 3) and onthree successive days (n 3) -e percent recoveries ( R)and the percent relative standard deviation ( RSD) werecalculated for each method

282 Assay of Zafatek Tablets -e absorbance spectrum ofthe tablet extract prepared under Sample Preparation wasrecorded -en the percent recoveries and standard de-viation were calculated

3 Results and Discussion

Calibration curves for the simultaneous equation methodwere constructed by plotting absorbance of TRG and TAD(Figures 3(a) and 3(b)) against the corresponding concen-trations A simultaneous equation at the specified lambdas(2740 nm and 2604 nm) was used to get the correspondingconcentration of TRG and TAD in their mixtures -en thepercent recoveries of both TRG and TADwere calculated forthe three laboratory-prepared mixtures (Table 1)

Calibration curves for the first-derivative method wereconstructed by plotting amplitudes of TRG and TAD(Figures 4(a) and 4(b)) against the corresponding concen-trations -e concentrations of TRG and TAD were

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

λmax of TAD = 2604λmax of TRG = 274

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

Zero-crossing point of TAD = 2604

Zero-crossing point of TRG = 274

(b)

Figure 2 Overlay of the absorption spectra (a) and first-derivative spectra (b) of TRG 30 microgmL (solid line) and TAD 15 microgmL(dashed line) using methanol as a blank

Journal of Analytical Methods in Chemistry 3

calculated by applying the corresponding regression equa-tions as shown in Table 2

For the mean-centering method the absorptionspectra of TRG and TAD were separately divided by thezero-order spectra of 50 μgmL TRG and 25 μgmL TAD toget the ratio spectra that were mean centered using theMinitab program Influences of different variables werestudied including divisor concentration and smoothingfactor Different concentrations were tried as divisors(30ndash60 μgmL of TRG and 15ndash35 μgmL of TAD) -e

selected divisors (50 μgmL TRG and 25 μgmL TAD)showed minimum noise maximum sensitivity andsmoother ratio spectra as shown in Figures 5(a) and 5(b)Mean centering was applicable as TRG and TAD arenoninteractive to each other and each of them obeysBeerrsquos law according to the following equation (Va ATRGCTRG +ATAD CTAD) where Va is the vector of absorbanceATRGndashATAD are the molar absorptivities and CTRGndashCTADare the concentrations of TRG and TAD respectivelyAfter division over ATAD the resultant ratio spectra

minus025

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 3 Overlay of the zero-order absorption spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL)(b) using methanol as a blank

Table 1 Results obtained by the proposed simultaneous equation spectrophotometric method for determination of TRG and TAD

Item TRG at 274 nm TRG at 2604 nm TAD at 274 nm TAD at 2604 nmRange of linearity (μgmL) 5ndash50 5ndash50 25ndash25 25ndash25

Regression equation A 00276CmiddotμgmL+ 00056

A 00208CmiddotμgmL+ 00063 A 00129CmiddotμgmLndash00050 A 00505CmiddotμgmLndash00117

Regression coefficient (r) 09999 09997 09990 09999LOD (μgmL) 101 μgmL 145 076 042LOQ (μgmL) 305 μgmL 441 232 127lowastSb 216times10minus4 235times10minus4 154times10minus4 328times10minus4lowastSa 0008 0009 0003 0006Confidence limit of the slope 00276times 595times10minus6 00208times 489times10minus6 00129times199times10minus6 00505times166times10minus5

Confidence limit of theintercept 00056times 450times10minus5 00063times 546times10minus5 minus00050times142times10minus5 minus00117times 711times10minus5

Standard error of theestimation 0009 0008 0003 0006

AccuracyLaboratory prepared(meanplusmn SD)

10066plusmn 010 10096plusmn 086

Standard addition (meanplusmnSD) 9855plusmn 170 mdash

PrecisionIntraday RSD 004ndash053ndash056 005ndash054ndash055

Interday RSD 040ndash054ndash092 045ndash052ndash092Drug in dosage form (meanplusmnSD) 10098plusmn 039 mdash

lowastStandard deviations of the slope Sb amp intercept Sa

4 Journal of Analytical Methods in Chemistry

were mean centered CTAD will be zero value enablingthe determination of CTRG without interference fromTAD and the same concept regarding ATRG as shown inTable 3

31 Validation according to ICH Guidelines

311 Linearity -e linearity of the calibration curves wasconfirmed by LODndashLOQ parameters STEYX Sb and Sa asshown in Tables 1ndash3 where LOD is the limit of detectionLOQ is the limit of quantification STEYX is the standarderror of estimation Sb is the standard deviation of the slopeand Sa is the standard deviation of the intercept Also themethods were adopted successfully for the assay of TRG and

TAD in their mixtures Acceptable results of the regressionparameters were achieved as shown in Tables 1ndash3 [14]

312 Accuracy and Precision Accuracy was checked bycalculating the percent recoveries of TRG and TAD in theirlaboratory-prepared mixtures while precision values werechecked using their intraday and interday records n 3 asshown in Tables 1ndash3

313 Specificity and Application on the PharmaceuticalDosage Form TRG was determined in its laboratory-prepared mixtures with TAD and in Zafatek tabletswithout interference from the excipients of the

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 4 Overlay of the first-order spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL) (b) usingmethanol as a blank

Table 2 Results obtained by the proposed first-derivative spectrophotometric method for determination of TRG and TAD

Item TRG at 2604 nm TAD at 274 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 00067CmiddotμgmLndash00008 A 00288CmiddotμgmLndash00094Regression coefficient (r) 09998 09997LOD (μgmL) 121 077LOQ (μgmL) 367 234lowastSb 631times10minus5 541times10minus4lowastSa 0002 0006Confidence limit of the slope 00067plusmn 423times10minus7 00288plusmn 993times10minus6

Confidence limit of the intercept minus00008plusmn 187times10minus6 minus00094plusmn 605times10minus5

Standard error of the estimation 0002 0006AccuracyLaboratory prepared (meanplusmn SD) 9943plusmn 078 9931plusmn 045

Standard addition (meanplusmn SD) 9951plusmn 136PrecisionIntraday RSD 045ndash053ndash071 043ndash051ndash064

Interday RSD 028ndash041ndash051 027ndash039ndash046Drug in dosage form (meanplusmn SD) 9937plusmn 089lowastStandard deviations of the slope Sb amp intercept Sa

Journal of Analytical Methods in Chemistry 5

pharmaceutical dosage form -e mean of the percentrecoveries and standard deviation were calculated asshown in Tables 1ndash3

32 Statistical Comparison ANOVA comparison of theproposed methods at p 005 showed no significant dif-ference as shown in Table 4

minus120minus100minus80minus60minus40minus20

020406080

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(a)

minus2

minus15

minus1

minus05

0

05

1

15

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(b)

Figure 5-emean-centered values of the ratio spectra representing 5ndash50 μgmL TRG divided by 25 μgmL of TAD (a) and the ratio spectraof 5ndash25 μgmL TAD divided by 50 μgmL of TRG (b) using methanol as a blank

Table 3 Results obtained by the proposed mean-centering spectrophotometric method for determination of TRG and TAD

Item TRG at 2876 nm TAD at 2572 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 13134CmiddotμgmL+ 02489 A 00451CmiddotμgmLndash00135Regression coefficient (r) 09999 09999LOD (μgmL) 098 042LOQ (μgmL) 298 129lowastSb 100times10minus2 297times10minus4lowastSa 0373 0006Confidence limit of the slope 13134plusmn 132times10minus2 00451plusmn 134times10minus5

Confidence limit of the intercept 02489plusmn 929times10minus minus00135plusmn 745times10minus5

Standard error of the estimation 0392 0006AccuracyLaboratory prepared (meanplusmn SD) 9999plusmn 014 10124plusmn 008

Standard deviation (meanplusmn SD) 9890plusmn 175PrecisionIntraday RSD 037ndash043ndash047 034ndash043ndash045

Interday RSD 016ndash027ndash076 016ndash025ndash073Drug in dosage form (meanplusmn SD) 9892plusmn 185lowastStandard deviations of the slope Sb amp intercept Sa

Table 4 Statistical comparison between the proposed spectrophotometric methods

Statistical termTRG TAD

Simultaneous equation First derivative Mean centering Simultaneous equation First derivative Mean centeringMean 10066 9943 9999 10096 9931 10124SDplusmn 010 078 014 086 045 008 RSD 010 078 014 085 045 008n 3 3 3 3 3 3V 001 061 002 074 020 001Note-e values in parentheses are the theoretical values at p 005 ANOVA results confirmed that there is no significant difference between groups of TRG(F 5350 and p 0046) and TAD (F 10320 and p 0011) at p 005

6 Journal of Analytical Methods in Chemistry

4 Conclusion

-e optimized analytical methods were confirmed to beprecise and accurate for determination of TRG and TADbased on the simple economic assay -e methods wereapplied successfully on the pharmaceutical dosage formwith acceptable validation results Simultaneous de-termination for laboratory-prepared mixtures of TRG andTAD was achieved through manipulating their zero-orderfirst-order and ratio spectra-e developed methods shouldbe of interest to the analysts in the area of drug control andcan be used by QC laboratories

Conflicts of Interest

-e authors declare that they have no conflicts of interest

References

[1] R N Kushwaha W Haq and S B Katti ldquoSixteen-years ofclinically relevant dipeptidyl peptidase-IV (DPP-IV) in-hibitors for treatment of type-2 diabetes a perspectiverdquoCurrent Medicinal Chemistry vol 21 no 35 pp 4013ndash40452014

[2] D Stoimenis T Karagiannis A Katsoula et al ldquoOnce-weeklydipeptidyl peptidase-4 inhibitors for type 2 diabetes a sys-tematic review and meta-analysisrdquo Expert Opinion on Phar-macotherapy vol 18 no 9 pp 843ndash851 2017

[3] N Harada and N Inagaki ldquoOnce-weekly DPP-4 inhibitorrdquoNihon Rinsho Japanese Journal of Clinical Medicine vol 73no 12 pp 2096ndash2102 2015

[4] K Kaku ldquoSafety evaluation of trelagliptin in the treatment ofJapanese type 2 diabetes mellitus patientsrdquo Expert Opinion onDrug Safety vol 16 no 11 pp 1313ndash1322 2017

[5] K McKeage ldquoTrelagliptin first global approvalrdquo Drugsvol 75 no 10 pp 1161ndash1164 2015

[6] K Kaku ldquoFirst novel once-weekly DPP-4 inhibitor trela-gliptin for the treatment of type 2 diabetes mellitusrdquo ExpertOpinion on Pharmacotherapy vol 16 no 16 pp 2539ndash25472015

[7] J Yang S P Zhan and H Y Zhang ldquoClinical applicationreview of the novel once-weekly DPP-4 inhibitor trelagliptinin the treatment of type 2 diabetesrdquo Chinese Journal of NewDrugs vol 26 no 2 pp 145ndash150 2017

[8] M Murakami N Hirahara H Morita and S Sasaki ldquoEfficacyand safety of trelagliptin a once-weekly dipeptidyl peptidase-4(DPP-4) inhibitor a non-inferiority study in switching fromdaily DPP-4 inhibitor for the treatment of type 2 diabetespatientsrdquo Journal of the Japan Diabetes Society vol 60 no 3pp 222ndash228 2017

[9] C E Grimshaw A Jennings R Kamran et al ldquoTrelagliptin(syr-472 Zafatek) novel once-weekly treatment for type 2diabetes inhibits dipeptidyl peptidase-4 (dpp-4) via a non-covalent mechanismrdquo PLoS One vol 11 no 6 Article ID0157509 2016

[10] X Hu T Lan Z Chen et al ldquoA rapid and sensitive UHPLC-MSMS assay for the determination of trelagliptin in ratplasma and its application to a pharmacokinetic studyrdquoJournal of Chromatography B Analytical Technologies in theBiomedical and Life Sciences vol 1033-1034 pp 166ndash171 2016

[11] Q Wang X Chen C Zhang et al ldquoDetermination of theenantiomeric purity of trelagliptin by pre-column de-rivatization and liquid chromatography on a chiral stationary

phaserdquo Chromatographia vol 78 no 21-22 pp 1395ndash14002015

[12] H Zhang L Sun L Zou et al ldquoIdentification character-ization and HPLC quantification of process-related impuritiesin trelagliptin succinate bulk drug six identified as newcompoundsrdquo Journal of Pharmaceutical and BiomedicalAnalysis vol 128 pp 18ndash27 2016

[13] S Deng Z Li J Jiang et al ldquoDetermination of relatedsubstances in trelagliptin succinate by RP-HPLC and iden-tification of impurities from acid degradation by LC-MSMSrdquoChinese Journal of New Drugs vol 25 no 2 pp 226ndash231 2016

[14] International Conference on Harmonization (ICH) Q2BValidation of Analytical Procedures Methodology 62 US FDAFederal Register Washington DC USA 1997

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26 Simultaneous Equation Method -e simultaneousequation spectrophotometric method was successfully ap-plied to TRG and TAD by manipulating their zero-orderabsorption spectra TRG and TAD showed the maximumabsorption (λmax) at 274 nm (λmax 1) and 2604 nm (λmax 2)respectively Absorbance at λmax 1 and λmax 2 was plottedagainst the corresponding concentrations of TRG and TADrespectively and calibration curves were constructedMixtures of TRG and TAD with different lambdas andconcentrations of TRG and TAD (CTRG and CTAD) can becalculated by a simultaneous equation -rough absorbanceof the sample at λ1 and λ2 (A1 and A2) absorptivities ofTRG at λmax 1 and λmax 2 (aTRG 1 and aTRG 2) and ab-sorptivities of TAD at λmax 1 and λmax 2 (aTAD 1 and aTAD 2)are as follows

CTRG A2lowast aTAD 1( 1113857minus A1lowast aTAD 2( 11138571113858 1113859

aTRG 2lowast aTAD 1( 1113857minus aTRG 1lowast aTAD 2( 11138571113858 1113859

CTAD A1lowast aTRG 2( 1113857minus A2lowast aTRG 1( 11138571113858 1113859

aTRG 2lowast aTAD 1( 1113857minus aTRG 1lowast aTAD 2( 11138571113858 1113859

(1)

-e total absorbance is the sum of TRG and TAD ab-sorbance as their λmax are relatively dissimilar and they donot interact chemically

27 First-Derivative Method -e first-derivative spectro-photometric method was successfully applied to TRG andTAD by manipulating their first-order spectra -e ampli-tudes of the first-order spectra were measured for TRG andTAD at 2604 nm and 274 nm respectively -en the am-plitudes were plotted against corresponding concentrationsof TRG and TAD to construct calibration curves

28 Mean-Centering Method -e scanned zero-orderspectra of TRG and TAD were separately divided by25 microgmL of TAD and 50 microgmL of TRG respectivelyUsing the Minitab v14 program the obtained ratio spectrawere mean centered and then the mean-centered values of

TRG and TAD were measured at 2876 nm and 2572 nmrespectively Calibration curves were constructed byplotting the mean-centered values against correspondingconcentrations

281 Accuracy and Precision -ree different ratios of thedrug and its degradation product (TAD equals to 10 15and 20 of TRG) as 3 laboratory-prepared mixtures wereapplied using concentrations corresponding to 35 40 and45 microgmL and 35 6 and 9 microgmL of TRG and TAD re-spectively-e zero-order absorption spectra of the mixtureswere recorded using methanol as a blank Finally the ob-tained spectra were manipulated by different methods tocalculate the corresponding concentration of each drugFurthermore they were analyzed using the proposedmethods three times within the same day (n 3) and onthree successive days (n 3) -e percent recoveries ( R)and the percent relative standard deviation ( RSD) werecalculated for each method

282 Assay of Zafatek Tablets -e absorbance spectrum ofthe tablet extract prepared under Sample Preparation wasrecorded -en the percent recoveries and standard de-viation were calculated

3 Results and Discussion

Calibration curves for the simultaneous equation methodwere constructed by plotting absorbance of TRG and TAD(Figures 3(a) and 3(b)) against the corresponding concen-trations A simultaneous equation at the specified lambdas(2740 nm and 2604 nm) was used to get the correspondingconcentration of TRG and TAD in their mixtures -en thepercent recoveries of both TRG and TADwere calculated forthe three laboratory-prepared mixtures (Table 1)

Calibration curves for the first-derivative method wereconstructed by plotting amplitudes of TRG and TAD(Figures 4(a) and 4(b)) against the corresponding concen-trations -e concentrations of TRG and TAD were

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

λmax of TAD = 2604λmax of TRG = 274

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

Zero-crossing point of TAD = 2604

Zero-crossing point of TRG = 274

(b)

Figure 2 Overlay of the absorption spectra (a) and first-derivative spectra (b) of TRG 30 microgmL (solid line) and TAD 15 microgmL(dashed line) using methanol as a blank

Journal of Analytical Methods in Chemistry 3

calculated by applying the corresponding regression equa-tions as shown in Table 2

For the mean-centering method the absorptionspectra of TRG and TAD were separately divided by thezero-order spectra of 50 μgmL TRG and 25 μgmL TAD toget the ratio spectra that were mean centered using theMinitab program Influences of different variables werestudied including divisor concentration and smoothingfactor Different concentrations were tried as divisors(30ndash60 μgmL of TRG and 15ndash35 μgmL of TAD) -e

selected divisors (50 μgmL TRG and 25 μgmL TAD)showed minimum noise maximum sensitivity andsmoother ratio spectra as shown in Figures 5(a) and 5(b)Mean centering was applicable as TRG and TAD arenoninteractive to each other and each of them obeysBeerrsquos law according to the following equation (Va ATRGCTRG +ATAD CTAD) where Va is the vector of absorbanceATRGndashATAD are the molar absorptivities and CTRGndashCTADare the concentrations of TRG and TAD respectivelyAfter division over ATAD the resultant ratio spectra

minus025

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 3 Overlay of the zero-order absorption spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL)(b) using methanol as a blank

Table 1 Results obtained by the proposed simultaneous equation spectrophotometric method for determination of TRG and TAD

Item TRG at 274 nm TRG at 2604 nm TAD at 274 nm TAD at 2604 nmRange of linearity (μgmL) 5ndash50 5ndash50 25ndash25 25ndash25

Regression equation A 00276CmiddotμgmL+ 00056

A 00208CmiddotμgmL+ 00063 A 00129CmiddotμgmLndash00050 A 00505CmiddotμgmLndash00117

Regression coefficient (r) 09999 09997 09990 09999LOD (μgmL) 101 μgmL 145 076 042LOQ (μgmL) 305 μgmL 441 232 127lowastSb 216times10minus4 235times10minus4 154times10minus4 328times10minus4lowastSa 0008 0009 0003 0006Confidence limit of the slope 00276times 595times10minus6 00208times 489times10minus6 00129times199times10minus6 00505times166times10minus5

Confidence limit of theintercept 00056times 450times10minus5 00063times 546times10minus5 minus00050times142times10minus5 minus00117times 711times10minus5

Standard error of theestimation 0009 0008 0003 0006

AccuracyLaboratory prepared(meanplusmn SD)

10066plusmn 010 10096plusmn 086

Standard addition (meanplusmnSD) 9855plusmn 170 mdash

PrecisionIntraday RSD 004ndash053ndash056 005ndash054ndash055

Interday RSD 040ndash054ndash092 045ndash052ndash092Drug in dosage form (meanplusmnSD) 10098plusmn 039 mdash

lowastStandard deviations of the slope Sb amp intercept Sa

4 Journal of Analytical Methods in Chemistry

were mean centered CTAD will be zero value enablingthe determination of CTRG without interference fromTAD and the same concept regarding ATRG as shown inTable 3

31 Validation according to ICH Guidelines

311 Linearity -e linearity of the calibration curves wasconfirmed by LODndashLOQ parameters STEYX Sb and Sa asshown in Tables 1ndash3 where LOD is the limit of detectionLOQ is the limit of quantification STEYX is the standarderror of estimation Sb is the standard deviation of the slopeand Sa is the standard deviation of the intercept Also themethods were adopted successfully for the assay of TRG and

TAD in their mixtures Acceptable results of the regressionparameters were achieved as shown in Tables 1ndash3 [14]

312 Accuracy and Precision Accuracy was checked bycalculating the percent recoveries of TRG and TAD in theirlaboratory-prepared mixtures while precision values werechecked using their intraday and interday records n 3 asshown in Tables 1ndash3

313 Specificity and Application on the PharmaceuticalDosage Form TRG was determined in its laboratory-prepared mixtures with TAD and in Zafatek tabletswithout interference from the excipients of the

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 4 Overlay of the first-order spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL) (b) usingmethanol as a blank

Table 2 Results obtained by the proposed first-derivative spectrophotometric method for determination of TRG and TAD

Item TRG at 2604 nm TAD at 274 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 00067CmiddotμgmLndash00008 A 00288CmiddotμgmLndash00094Regression coefficient (r) 09998 09997LOD (μgmL) 121 077LOQ (μgmL) 367 234lowastSb 631times10minus5 541times10minus4lowastSa 0002 0006Confidence limit of the slope 00067plusmn 423times10minus7 00288plusmn 993times10minus6

Confidence limit of the intercept minus00008plusmn 187times10minus6 minus00094plusmn 605times10minus5

Standard error of the estimation 0002 0006AccuracyLaboratory prepared (meanplusmn SD) 9943plusmn 078 9931plusmn 045

Standard addition (meanplusmn SD) 9951plusmn 136PrecisionIntraday RSD 045ndash053ndash071 043ndash051ndash064

Interday RSD 028ndash041ndash051 027ndash039ndash046Drug in dosage form (meanplusmn SD) 9937plusmn 089lowastStandard deviations of the slope Sb amp intercept Sa

Journal of Analytical Methods in Chemistry 5

pharmaceutical dosage form -e mean of the percentrecoveries and standard deviation were calculated asshown in Tables 1ndash3

32 Statistical Comparison ANOVA comparison of theproposed methods at p 005 showed no significant dif-ference as shown in Table 4

minus120minus100minus80minus60minus40minus20

020406080

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(a)

minus2

minus15

minus1

minus05

0

05

1

15

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(b)

Figure 5-emean-centered values of the ratio spectra representing 5ndash50 μgmL TRG divided by 25 μgmL of TAD (a) and the ratio spectraof 5ndash25 μgmL TAD divided by 50 μgmL of TRG (b) using methanol as a blank

Table 3 Results obtained by the proposed mean-centering spectrophotometric method for determination of TRG and TAD

Item TRG at 2876 nm TAD at 2572 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 13134CmiddotμgmL+ 02489 A 00451CmiddotμgmLndash00135Regression coefficient (r) 09999 09999LOD (μgmL) 098 042LOQ (μgmL) 298 129lowastSb 100times10minus2 297times10minus4lowastSa 0373 0006Confidence limit of the slope 13134plusmn 132times10minus2 00451plusmn 134times10minus5

Confidence limit of the intercept 02489plusmn 929times10minus minus00135plusmn 745times10minus5

Standard error of the estimation 0392 0006AccuracyLaboratory prepared (meanplusmn SD) 9999plusmn 014 10124plusmn 008

Standard deviation (meanplusmn SD) 9890plusmn 175PrecisionIntraday RSD 037ndash043ndash047 034ndash043ndash045

Interday RSD 016ndash027ndash076 016ndash025ndash073Drug in dosage form (meanplusmn SD) 9892plusmn 185lowastStandard deviations of the slope Sb amp intercept Sa

Table 4 Statistical comparison between the proposed spectrophotometric methods

Statistical termTRG TAD

Simultaneous equation First derivative Mean centering Simultaneous equation First derivative Mean centeringMean 10066 9943 9999 10096 9931 10124SDplusmn 010 078 014 086 045 008 RSD 010 078 014 085 045 008n 3 3 3 3 3 3V 001 061 002 074 020 001Note-e values in parentheses are the theoretical values at p 005 ANOVA results confirmed that there is no significant difference between groups of TRG(F 5350 and p 0046) and TAD (F 10320 and p 0011) at p 005

6 Journal of Analytical Methods in Chemistry

4 Conclusion

-e optimized analytical methods were confirmed to beprecise and accurate for determination of TRG and TADbased on the simple economic assay -e methods wereapplied successfully on the pharmaceutical dosage formwith acceptable validation results Simultaneous de-termination for laboratory-prepared mixtures of TRG andTAD was achieved through manipulating their zero-orderfirst-order and ratio spectra-e developed methods shouldbe of interest to the analysts in the area of drug control andcan be used by QC laboratories

Conflicts of Interest

-e authors declare that they have no conflicts of interest

References

[1] R N Kushwaha W Haq and S B Katti ldquoSixteen-years ofclinically relevant dipeptidyl peptidase-IV (DPP-IV) in-hibitors for treatment of type-2 diabetes a perspectiverdquoCurrent Medicinal Chemistry vol 21 no 35 pp 4013ndash40452014

[2] D Stoimenis T Karagiannis A Katsoula et al ldquoOnce-weeklydipeptidyl peptidase-4 inhibitors for type 2 diabetes a sys-tematic review and meta-analysisrdquo Expert Opinion on Phar-macotherapy vol 18 no 9 pp 843ndash851 2017

[3] N Harada and N Inagaki ldquoOnce-weekly DPP-4 inhibitorrdquoNihon Rinsho Japanese Journal of Clinical Medicine vol 73no 12 pp 2096ndash2102 2015

[4] K Kaku ldquoSafety evaluation of trelagliptin in the treatment ofJapanese type 2 diabetes mellitus patientsrdquo Expert Opinion onDrug Safety vol 16 no 11 pp 1313ndash1322 2017

[5] K McKeage ldquoTrelagliptin first global approvalrdquo Drugsvol 75 no 10 pp 1161ndash1164 2015

[6] K Kaku ldquoFirst novel once-weekly DPP-4 inhibitor trela-gliptin for the treatment of type 2 diabetes mellitusrdquo ExpertOpinion on Pharmacotherapy vol 16 no 16 pp 2539ndash25472015

[7] J Yang S P Zhan and H Y Zhang ldquoClinical applicationreview of the novel once-weekly DPP-4 inhibitor trelagliptinin the treatment of type 2 diabetesrdquo Chinese Journal of NewDrugs vol 26 no 2 pp 145ndash150 2017

[8] M Murakami N Hirahara H Morita and S Sasaki ldquoEfficacyand safety of trelagliptin a once-weekly dipeptidyl peptidase-4(DPP-4) inhibitor a non-inferiority study in switching fromdaily DPP-4 inhibitor for the treatment of type 2 diabetespatientsrdquo Journal of the Japan Diabetes Society vol 60 no 3pp 222ndash228 2017

[9] C E Grimshaw A Jennings R Kamran et al ldquoTrelagliptin(syr-472 Zafatek) novel once-weekly treatment for type 2diabetes inhibits dipeptidyl peptidase-4 (dpp-4) via a non-covalent mechanismrdquo PLoS One vol 11 no 6 Article ID0157509 2016

[10] X Hu T Lan Z Chen et al ldquoA rapid and sensitive UHPLC-MSMS assay for the determination of trelagliptin in ratplasma and its application to a pharmacokinetic studyrdquoJournal of Chromatography B Analytical Technologies in theBiomedical and Life Sciences vol 1033-1034 pp 166ndash171 2016

[11] Q Wang X Chen C Zhang et al ldquoDetermination of theenantiomeric purity of trelagliptin by pre-column de-rivatization and liquid chromatography on a chiral stationary

phaserdquo Chromatographia vol 78 no 21-22 pp 1395ndash14002015

[12] H Zhang L Sun L Zou et al ldquoIdentification character-ization and HPLC quantification of process-related impuritiesin trelagliptin succinate bulk drug six identified as newcompoundsrdquo Journal of Pharmaceutical and BiomedicalAnalysis vol 128 pp 18ndash27 2016

[13] S Deng Z Li J Jiang et al ldquoDetermination of relatedsubstances in trelagliptin succinate by RP-HPLC and iden-tification of impurities from acid degradation by LC-MSMSrdquoChinese Journal of New Drugs vol 25 no 2 pp 226ndash231 2016

[14] International Conference on Harmonization (ICH) Q2BValidation of Analytical Procedures Methodology 62 US FDAFederal Register Washington DC USA 1997

Journal of Analytical Methods in Chemistry 7

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

calculated by applying the corresponding regression equa-tions as shown in Table 2

For the mean-centering method the absorptionspectra of TRG and TAD were separately divided by thezero-order spectra of 50 μgmL TRG and 25 μgmL TAD toget the ratio spectra that were mean centered using theMinitab program Influences of different variables werestudied including divisor concentration and smoothingfactor Different concentrations were tried as divisors(30ndash60 μgmL of TRG and 15ndash35 μgmL of TAD) -e

selected divisors (50 μgmL TRG and 25 μgmL TAD)showed minimum noise maximum sensitivity andsmoother ratio spectra as shown in Figures 5(a) and 5(b)Mean centering was applicable as TRG and TAD arenoninteractive to each other and each of them obeysBeerrsquos law according to the following equation (Va ATRGCTRG +ATAD CTAD) where Va is the vector of absorbanceATRGndashATAD are the molar absorptivities and CTRGndashCTADare the concentrations of TRG and TAD respectivelyAfter division over ATAD the resultant ratio spectra

minus025

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 3 Overlay of the zero-order absorption spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL)(b) using methanol as a blank

Table 1 Results obtained by the proposed simultaneous equation spectrophotometric method for determination of TRG and TAD

Item TRG at 274 nm TRG at 2604 nm TAD at 274 nm TAD at 2604 nmRange of linearity (μgmL) 5ndash50 5ndash50 25ndash25 25ndash25

Regression equation A 00276CmiddotμgmL+ 00056

A 00208CmiddotμgmL+ 00063 A 00129CmiddotμgmLndash00050 A 00505CmiddotμgmLndash00117

Regression coefficient (r) 09999 09997 09990 09999LOD (μgmL) 101 μgmL 145 076 042LOQ (μgmL) 305 μgmL 441 232 127lowastSb 216times10minus4 235times10minus4 154times10minus4 328times10minus4lowastSa 0008 0009 0003 0006Confidence limit of the slope 00276times 595times10minus6 00208times 489times10minus6 00129times199times10minus6 00505times166times10minus5

Confidence limit of theintercept 00056times 450times10minus5 00063times 546times10minus5 minus00050times142times10minus5 minus00117times 711times10minus5

Standard error of theestimation 0009 0008 0003 0006

AccuracyLaboratory prepared(meanplusmn SD)

10066plusmn 010 10096plusmn 086

Standard addition (meanplusmnSD) 9855plusmn 170 mdash

PrecisionIntraday RSD 004ndash053ndash056 005ndash054ndash055

Interday RSD 040ndash054ndash092 045ndash052ndash092Drug in dosage form (meanplusmnSD) 10098plusmn 039 mdash

lowastStandard deviations of the slope Sb amp intercept Sa

4 Journal of Analytical Methods in Chemistry

were mean centered CTAD will be zero value enablingthe determination of CTRG without interference fromTAD and the same concept regarding ATRG as shown inTable 3

31 Validation according to ICH Guidelines

311 Linearity -e linearity of the calibration curves wasconfirmed by LODndashLOQ parameters STEYX Sb and Sa asshown in Tables 1ndash3 where LOD is the limit of detectionLOQ is the limit of quantification STEYX is the standarderror of estimation Sb is the standard deviation of the slopeand Sa is the standard deviation of the intercept Also themethods were adopted successfully for the assay of TRG and

TAD in their mixtures Acceptable results of the regressionparameters were achieved as shown in Tables 1ndash3 [14]

312 Accuracy and Precision Accuracy was checked bycalculating the percent recoveries of TRG and TAD in theirlaboratory-prepared mixtures while precision values werechecked using their intraday and interday records n 3 asshown in Tables 1ndash3

313 Specificity and Application on the PharmaceuticalDosage Form TRG was determined in its laboratory-prepared mixtures with TAD and in Zafatek tabletswithout interference from the excipients of the

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 4 Overlay of the first-order spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL) (b) usingmethanol as a blank

Table 2 Results obtained by the proposed first-derivative spectrophotometric method for determination of TRG and TAD

Item TRG at 2604 nm TAD at 274 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 00067CmiddotμgmLndash00008 A 00288CmiddotμgmLndash00094Regression coefficient (r) 09998 09997LOD (μgmL) 121 077LOQ (μgmL) 367 234lowastSb 631times10minus5 541times10minus4lowastSa 0002 0006Confidence limit of the slope 00067plusmn 423times10minus7 00288plusmn 993times10minus6

Confidence limit of the intercept minus00008plusmn 187times10minus6 minus00094plusmn 605times10minus5

Standard error of the estimation 0002 0006AccuracyLaboratory prepared (meanplusmn SD) 9943plusmn 078 9931plusmn 045

Standard addition (meanplusmn SD) 9951plusmn 136PrecisionIntraday RSD 045ndash053ndash071 043ndash051ndash064

Interday RSD 028ndash041ndash051 027ndash039ndash046Drug in dosage form (meanplusmn SD) 9937plusmn 089lowastStandard deviations of the slope Sb amp intercept Sa

Journal of Analytical Methods in Chemistry 5

pharmaceutical dosage form -e mean of the percentrecoveries and standard deviation were calculated asshown in Tables 1ndash3

32 Statistical Comparison ANOVA comparison of theproposed methods at p 005 showed no significant dif-ference as shown in Table 4

minus120minus100minus80minus60minus40minus20

020406080

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(a)

minus2

minus15

minus1

minus05

0

05

1

15

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(b)

Figure 5-emean-centered values of the ratio spectra representing 5ndash50 μgmL TRG divided by 25 μgmL of TAD (a) and the ratio spectraof 5ndash25 μgmL TAD divided by 50 μgmL of TRG (b) using methanol as a blank

Table 3 Results obtained by the proposed mean-centering spectrophotometric method for determination of TRG and TAD

Item TRG at 2876 nm TAD at 2572 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 13134CmiddotμgmL+ 02489 A 00451CmiddotμgmLndash00135Regression coefficient (r) 09999 09999LOD (μgmL) 098 042LOQ (μgmL) 298 129lowastSb 100times10minus2 297times10minus4lowastSa 0373 0006Confidence limit of the slope 13134plusmn 132times10minus2 00451plusmn 134times10minus5

Confidence limit of the intercept 02489plusmn 929times10minus minus00135plusmn 745times10minus5

Standard error of the estimation 0392 0006AccuracyLaboratory prepared (meanplusmn SD) 9999plusmn 014 10124plusmn 008

Standard deviation (meanplusmn SD) 9890plusmn 175PrecisionIntraday RSD 037ndash043ndash047 034ndash043ndash045

Interday RSD 016ndash027ndash076 016ndash025ndash073Drug in dosage form (meanplusmn SD) 9892plusmn 185lowastStandard deviations of the slope Sb amp intercept Sa

Table 4 Statistical comparison between the proposed spectrophotometric methods

Statistical termTRG TAD

Simultaneous equation First derivative Mean centering Simultaneous equation First derivative Mean centeringMean 10066 9943 9999 10096 9931 10124SDplusmn 010 078 014 086 045 008 RSD 010 078 014 085 045 008n 3 3 3 3 3 3V 001 061 002 074 020 001Note-e values in parentheses are the theoretical values at p 005 ANOVA results confirmed that there is no significant difference between groups of TRG(F 5350 and p 0046) and TAD (F 10320 and p 0011) at p 005

6 Journal of Analytical Methods in Chemistry

4 Conclusion

-e optimized analytical methods were confirmed to beprecise and accurate for determination of TRG and TADbased on the simple economic assay -e methods wereapplied successfully on the pharmaceutical dosage formwith acceptable validation results Simultaneous de-termination for laboratory-prepared mixtures of TRG andTAD was achieved through manipulating their zero-orderfirst-order and ratio spectra-e developed methods shouldbe of interest to the analysts in the area of drug control andcan be used by QC laboratories

Conflicts of Interest

-e authors declare that they have no conflicts of interest

References

[1] R N Kushwaha W Haq and S B Katti ldquoSixteen-years ofclinically relevant dipeptidyl peptidase-IV (DPP-IV) in-hibitors for treatment of type-2 diabetes a perspectiverdquoCurrent Medicinal Chemistry vol 21 no 35 pp 4013ndash40452014

[2] D Stoimenis T Karagiannis A Katsoula et al ldquoOnce-weeklydipeptidyl peptidase-4 inhibitors for type 2 diabetes a sys-tematic review and meta-analysisrdquo Expert Opinion on Phar-macotherapy vol 18 no 9 pp 843ndash851 2017

[3] N Harada and N Inagaki ldquoOnce-weekly DPP-4 inhibitorrdquoNihon Rinsho Japanese Journal of Clinical Medicine vol 73no 12 pp 2096ndash2102 2015

[4] K Kaku ldquoSafety evaluation of trelagliptin in the treatment ofJapanese type 2 diabetes mellitus patientsrdquo Expert Opinion onDrug Safety vol 16 no 11 pp 1313ndash1322 2017

[5] K McKeage ldquoTrelagliptin first global approvalrdquo Drugsvol 75 no 10 pp 1161ndash1164 2015

[6] K Kaku ldquoFirst novel once-weekly DPP-4 inhibitor trela-gliptin for the treatment of type 2 diabetes mellitusrdquo ExpertOpinion on Pharmacotherapy vol 16 no 16 pp 2539ndash25472015

[7] J Yang S P Zhan and H Y Zhang ldquoClinical applicationreview of the novel once-weekly DPP-4 inhibitor trelagliptinin the treatment of type 2 diabetesrdquo Chinese Journal of NewDrugs vol 26 no 2 pp 145ndash150 2017

[8] M Murakami N Hirahara H Morita and S Sasaki ldquoEfficacyand safety of trelagliptin a once-weekly dipeptidyl peptidase-4(DPP-4) inhibitor a non-inferiority study in switching fromdaily DPP-4 inhibitor for the treatment of type 2 diabetespatientsrdquo Journal of the Japan Diabetes Society vol 60 no 3pp 222ndash228 2017

[9] C E Grimshaw A Jennings R Kamran et al ldquoTrelagliptin(syr-472 Zafatek) novel once-weekly treatment for type 2diabetes inhibits dipeptidyl peptidase-4 (dpp-4) via a non-covalent mechanismrdquo PLoS One vol 11 no 6 Article ID0157509 2016

[10] X Hu T Lan Z Chen et al ldquoA rapid and sensitive UHPLC-MSMS assay for the determination of trelagliptin in ratplasma and its application to a pharmacokinetic studyrdquoJournal of Chromatography B Analytical Technologies in theBiomedical and Life Sciences vol 1033-1034 pp 166ndash171 2016

[11] Q Wang X Chen C Zhang et al ldquoDetermination of theenantiomeric purity of trelagliptin by pre-column de-rivatization and liquid chromatography on a chiral stationary

phaserdquo Chromatographia vol 78 no 21-22 pp 1395ndash14002015

[12] H Zhang L Sun L Zou et al ldquoIdentification character-ization and HPLC quantification of process-related impuritiesin trelagliptin succinate bulk drug six identified as newcompoundsrdquo Journal of Pharmaceutical and BiomedicalAnalysis vol 128 pp 18ndash27 2016

[13] S Deng Z Li J Jiang et al ldquoDetermination of relatedsubstances in trelagliptin succinate by RP-HPLC and iden-tification of impurities from acid degradation by LC-MSMSrdquoChinese Journal of New Drugs vol 25 no 2 pp 226ndash231 2016

[14] International Conference on Harmonization (ICH) Q2BValidation of Analytical Procedures Methodology 62 US FDAFederal Register Washington DC USA 1997

Journal of Analytical Methods in Chemistry 7

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

were mean centered CTAD will be zero value enablingthe determination of CTRG without interference fromTAD and the same concept regarding ATRG as shown inTable 3

31 Validation according to ICH Guidelines

311 Linearity -e linearity of the calibration curves wasconfirmed by LODndashLOQ parameters STEYX Sb and Sa asshown in Tables 1ndash3 where LOD is the limit of detectionLOQ is the limit of quantification STEYX is the standarderror of estimation Sb is the standard deviation of the slopeand Sa is the standard deviation of the intercept Also themethods were adopted successfully for the assay of TRG and

TAD in their mixtures Acceptable results of the regressionparameters were achieved as shown in Tables 1ndash3 [14]

312 Accuracy and Precision Accuracy was checked bycalculating the percent recoveries of TRG and TAD in theirlaboratory-prepared mixtures while precision values werechecked using their intraday and interday records n 3 asshown in Tables 1ndash3

313 Specificity and Application on the PharmaceuticalDosage Form TRG was determined in its laboratory-prepared mixtures with TAD and in Zafatek tabletswithout interference from the excipients of the

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(a)

minus1

3

0

1

2

220 320240 260 280 300

Abs

orba

nce

Wavelength (nm)

(b)

Figure 4 Overlay of the first-order spectra of TRG (5 10 20 30 40 and 50 microgmL) (a) and TAD (25 5 10 15 20 and 25 microgmL) (b) usingmethanol as a blank

Table 2 Results obtained by the proposed first-derivative spectrophotometric method for determination of TRG and TAD

Item TRG at 2604 nm TAD at 274 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 00067CmiddotμgmLndash00008 A 00288CmiddotμgmLndash00094Regression coefficient (r) 09998 09997LOD (μgmL) 121 077LOQ (μgmL) 367 234lowastSb 631times10minus5 541times10minus4lowastSa 0002 0006Confidence limit of the slope 00067plusmn 423times10minus7 00288plusmn 993times10minus6

Confidence limit of the intercept minus00008plusmn 187times10minus6 minus00094plusmn 605times10minus5

Standard error of the estimation 0002 0006AccuracyLaboratory prepared (meanplusmn SD) 9943plusmn 078 9931plusmn 045

Standard addition (meanplusmn SD) 9951plusmn 136PrecisionIntraday RSD 045ndash053ndash071 043ndash051ndash064

Interday RSD 028ndash041ndash051 027ndash039ndash046Drug in dosage form (meanplusmn SD) 9937plusmn 089lowastStandard deviations of the slope Sb amp intercept Sa

Journal of Analytical Methods in Chemistry 5

pharmaceutical dosage form -e mean of the percentrecoveries and standard deviation were calculated asshown in Tables 1ndash3

32 Statistical Comparison ANOVA comparison of theproposed methods at p 005 showed no significant dif-ference as shown in Table 4

minus120minus100minus80minus60minus40minus20

020406080

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(a)

minus2

minus15

minus1

minus05

0

05

1

15

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(b)

Figure 5-emean-centered values of the ratio spectra representing 5ndash50 μgmL TRG divided by 25 μgmL of TAD (a) and the ratio spectraof 5ndash25 μgmL TAD divided by 50 μgmL of TRG (b) using methanol as a blank

Table 3 Results obtained by the proposed mean-centering spectrophotometric method for determination of TRG and TAD

Item TRG at 2876 nm TAD at 2572 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 13134CmiddotμgmL+ 02489 A 00451CmiddotμgmLndash00135Regression coefficient (r) 09999 09999LOD (μgmL) 098 042LOQ (μgmL) 298 129lowastSb 100times10minus2 297times10minus4lowastSa 0373 0006Confidence limit of the slope 13134plusmn 132times10minus2 00451plusmn 134times10minus5

Confidence limit of the intercept 02489plusmn 929times10minus minus00135plusmn 745times10minus5

Standard error of the estimation 0392 0006AccuracyLaboratory prepared (meanplusmn SD) 9999plusmn 014 10124plusmn 008

Standard deviation (meanplusmn SD) 9890plusmn 175PrecisionIntraday RSD 037ndash043ndash047 034ndash043ndash045

Interday RSD 016ndash027ndash076 016ndash025ndash073Drug in dosage form (meanplusmn SD) 9892plusmn 185lowastStandard deviations of the slope Sb amp intercept Sa

Table 4 Statistical comparison between the proposed spectrophotometric methods

Statistical termTRG TAD

Simultaneous equation First derivative Mean centering Simultaneous equation First derivative Mean centeringMean 10066 9943 9999 10096 9931 10124SDplusmn 010 078 014 086 045 008 RSD 010 078 014 085 045 008n 3 3 3 3 3 3V 001 061 002 074 020 001Note-e values in parentheses are the theoretical values at p 005 ANOVA results confirmed that there is no significant difference between groups of TRG(F 5350 and p 0046) and TAD (F 10320 and p 0011) at p 005

6 Journal of Analytical Methods in Chemistry

4 Conclusion

-e optimized analytical methods were confirmed to beprecise and accurate for determination of TRG and TADbased on the simple economic assay -e methods wereapplied successfully on the pharmaceutical dosage formwith acceptable validation results Simultaneous de-termination for laboratory-prepared mixtures of TRG andTAD was achieved through manipulating their zero-orderfirst-order and ratio spectra-e developed methods shouldbe of interest to the analysts in the area of drug control andcan be used by QC laboratories

Conflicts of Interest

-e authors declare that they have no conflicts of interest

References

[1] R N Kushwaha W Haq and S B Katti ldquoSixteen-years ofclinically relevant dipeptidyl peptidase-IV (DPP-IV) in-hibitors for treatment of type-2 diabetes a perspectiverdquoCurrent Medicinal Chemistry vol 21 no 35 pp 4013ndash40452014

[2] D Stoimenis T Karagiannis A Katsoula et al ldquoOnce-weeklydipeptidyl peptidase-4 inhibitors for type 2 diabetes a sys-tematic review and meta-analysisrdquo Expert Opinion on Phar-macotherapy vol 18 no 9 pp 843ndash851 2017

[3] N Harada and N Inagaki ldquoOnce-weekly DPP-4 inhibitorrdquoNihon Rinsho Japanese Journal of Clinical Medicine vol 73no 12 pp 2096ndash2102 2015

[4] K Kaku ldquoSafety evaluation of trelagliptin in the treatment ofJapanese type 2 diabetes mellitus patientsrdquo Expert Opinion onDrug Safety vol 16 no 11 pp 1313ndash1322 2017

[5] K McKeage ldquoTrelagliptin first global approvalrdquo Drugsvol 75 no 10 pp 1161ndash1164 2015

[6] K Kaku ldquoFirst novel once-weekly DPP-4 inhibitor trela-gliptin for the treatment of type 2 diabetes mellitusrdquo ExpertOpinion on Pharmacotherapy vol 16 no 16 pp 2539ndash25472015

[7] J Yang S P Zhan and H Y Zhang ldquoClinical applicationreview of the novel once-weekly DPP-4 inhibitor trelagliptinin the treatment of type 2 diabetesrdquo Chinese Journal of NewDrugs vol 26 no 2 pp 145ndash150 2017

[8] M Murakami N Hirahara H Morita and S Sasaki ldquoEfficacyand safety of trelagliptin a once-weekly dipeptidyl peptidase-4(DPP-4) inhibitor a non-inferiority study in switching fromdaily DPP-4 inhibitor for the treatment of type 2 diabetespatientsrdquo Journal of the Japan Diabetes Society vol 60 no 3pp 222ndash228 2017

[9] C E Grimshaw A Jennings R Kamran et al ldquoTrelagliptin(syr-472 Zafatek) novel once-weekly treatment for type 2diabetes inhibits dipeptidyl peptidase-4 (dpp-4) via a non-covalent mechanismrdquo PLoS One vol 11 no 6 Article ID0157509 2016

[10] X Hu T Lan Z Chen et al ldquoA rapid and sensitive UHPLC-MSMS assay for the determination of trelagliptin in ratplasma and its application to a pharmacokinetic studyrdquoJournal of Chromatography B Analytical Technologies in theBiomedical and Life Sciences vol 1033-1034 pp 166ndash171 2016

[11] Q Wang X Chen C Zhang et al ldquoDetermination of theenantiomeric purity of trelagliptin by pre-column de-rivatization and liquid chromatography on a chiral stationary

phaserdquo Chromatographia vol 78 no 21-22 pp 1395ndash14002015

[12] H Zhang L Sun L Zou et al ldquoIdentification character-ization and HPLC quantification of process-related impuritiesin trelagliptin succinate bulk drug six identified as newcompoundsrdquo Journal of Pharmaceutical and BiomedicalAnalysis vol 128 pp 18ndash27 2016

[13] S Deng Z Li J Jiang et al ldquoDetermination of relatedsubstances in trelagliptin succinate by RP-HPLC and iden-tification of impurities from acid degradation by LC-MSMSrdquoChinese Journal of New Drugs vol 25 no 2 pp 226ndash231 2016

[14] International Conference on Harmonization (ICH) Q2BValidation of Analytical Procedures Methodology 62 US FDAFederal Register Washington DC USA 1997

Journal of Analytical Methods in Chemistry 7

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

pharmaceutical dosage form -e mean of the percentrecoveries and standard deviation were calculated asshown in Tables 1ndash3

32 Statistical Comparison ANOVA comparison of theproposed methods at p 005 showed no significant dif-ference as shown in Table 4

minus120minus100minus80minus60minus40minus20

020406080

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(a)

minus2

minus15

minus1

minus05

0

05

1

15

220 240 260 280 300 320

Mea

n-ce

nter

ed va

lues

Wavelength (nm)

(b)

Figure 5-emean-centered values of the ratio spectra representing 5ndash50 μgmL TRG divided by 25 μgmL of TAD (a) and the ratio spectraof 5ndash25 μgmL TAD divided by 50 μgmL of TRG (b) using methanol as a blank

Table 3 Results obtained by the proposed mean-centering spectrophotometric method for determination of TRG and TAD

Item TRG at 2876 nm TAD at 2572 nmRange of linearity (μgmL) 5ndash50 25ndash25Regression equation A 13134CmiddotμgmL+ 02489 A 00451CmiddotμgmLndash00135Regression coefficient (r) 09999 09999LOD (μgmL) 098 042LOQ (μgmL) 298 129lowastSb 100times10minus2 297times10minus4lowastSa 0373 0006Confidence limit of the slope 13134plusmn 132times10minus2 00451plusmn 134times10minus5

Confidence limit of the intercept 02489plusmn 929times10minus minus00135plusmn 745times10minus5

Standard error of the estimation 0392 0006AccuracyLaboratory prepared (meanplusmn SD) 9999plusmn 014 10124plusmn 008

Standard deviation (meanplusmn SD) 9890plusmn 175PrecisionIntraday RSD 037ndash043ndash047 034ndash043ndash045

Interday RSD 016ndash027ndash076 016ndash025ndash073Drug in dosage form (meanplusmn SD) 9892plusmn 185lowastStandard deviations of the slope Sb amp intercept Sa

Table 4 Statistical comparison between the proposed spectrophotometric methods

Statistical termTRG TAD

Simultaneous equation First derivative Mean centering Simultaneous equation First derivative Mean centeringMean 10066 9943 9999 10096 9931 10124SDplusmn 010 078 014 086 045 008 RSD 010 078 014 085 045 008n 3 3 3 3 3 3V 001 061 002 074 020 001Note-e values in parentheses are the theoretical values at p 005 ANOVA results confirmed that there is no significant difference between groups of TRG(F 5350 and p 0046) and TAD (F 10320 and p 0011) at p 005

6 Journal of Analytical Methods in Chemistry

4 Conclusion

-e optimized analytical methods were confirmed to beprecise and accurate for determination of TRG and TADbased on the simple economic assay -e methods wereapplied successfully on the pharmaceutical dosage formwith acceptable validation results Simultaneous de-termination for laboratory-prepared mixtures of TRG andTAD was achieved through manipulating their zero-orderfirst-order and ratio spectra-e developed methods shouldbe of interest to the analysts in the area of drug control andcan be used by QC laboratories

Conflicts of Interest

-e authors declare that they have no conflicts of interest

References

[1] R N Kushwaha W Haq and S B Katti ldquoSixteen-years ofclinically relevant dipeptidyl peptidase-IV (DPP-IV) in-hibitors for treatment of type-2 diabetes a perspectiverdquoCurrent Medicinal Chemistry vol 21 no 35 pp 4013ndash40452014

[2] D Stoimenis T Karagiannis A Katsoula et al ldquoOnce-weeklydipeptidyl peptidase-4 inhibitors for type 2 diabetes a sys-tematic review and meta-analysisrdquo Expert Opinion on Phar-macotherapy vol 18 no 9 pp 843ndash851 2017

[3] N Harada and N Inagaki ldquoOnce-weekly DPP-4 inhibitorrdquoNihon Rinsho Japanese Journal of Clinical Medicine vol 73no 12 pp 2096ndash2102 2015

[4] K Kaku ldquoSafety evaluation of trelagliptin in the treatment ofJapanese type 2 diabetes mellitus patientsrdquo Expert Opinion onDrug Safety vol 16 no 11 pp 1313ndash1322 2017

[5] K McKeage ldquoTrelagliptin first global approvalrdquo Drugsvol 75 no 10 pp 1161ndash1164 2015

[6] K Kaku ldquoFirst novel once-weekly DPP-4 inhibitor trela-gliptin for the treatment of type 2 diabetes mellitusrdquo ExpertOpinion on Pharmacotherapy vol 16 no 16 pp 2539ndash25472015

[7] J Yang S P Zhan and H Y Zhang ldquoClinical applicationreview of the novel once-weekly DPP-4 inhibitor trelagliptinin the treatment of type 2 diabetesrdquo Chinese Journal of NewDrugs vol 26 no 2 pp 145ndash150 2017

[8] M Murakami N Hirahara H Morita and S Sasaki ldquoEfficacyand safety of trelagliptin a once-weekly dipeptidyl peptidase-4(DPP-4) inhibitor a non-inferiority study in switching fromdaily DPP-4 inhibitor for the treatment of type 2 diabetespatientsrdquo Journal of the Japan Diabetes Society vol 60 no 3pp 222ndash228 2017

[9] C E Grimshaw A Jennings R Kamran et al ldquoTrelagliptin(syr-472 Zafatek) novel once-weekly treatment for type 2diabetes inhibits dipeptidyl peptidase-4 (dpp-4) via a non-covalent mechanismrdquo PLoS One vol 11 no 6 Article ID0157509 2016

[10] X Hu T Lan Z Chen et al ldquoA rapid and sensitive UHPLC-MSMS assay for the determination of trelagliptin in ratplasma and its application to a pharmacokinetic studyrdquoJournal of Chromatography B Analytical Technologies in theBiomedical and Life Sciences vol 1033-1034 pp 166ndash171 2016

[11] Q Wang X Chen C Zhang et al ldquoDetermination of theenantiomeric purity of trelagliptin by pre-column de-rivatization and liquid chromatography on a chiral stationary

phaserdquo Chromatographia vol 78 no 21-22 pp 1395ndash14002015

[12] H Zhang L Sun L Zou et al ldquoIdentification character-ization and HPLC quantification of process-related impuritiesin trelagliptin succinate bulk drug six identified as newcompoundsrdquo Journal of Pharmaceutical and BiomedicalAnalysis vol 128 pp 18ndash27 2016

[13] S Deng Z Li J Jiang et al ldquoDetermination of relatedsubstances in trelagliptin succinate by RP-HPLC and iden-tification of impurities from acid degradation by LC-MSMSrdquoChinese Journal of New Drugs vol 25 no 2 pp 226ndash231 2016

[14] International Conference on Harmonization (ICH) Q2BValidation of Analytical Procedures Methodology 62 US FDAFederal Register Washington DC USA 1997

Journal of Analytical Methods in Chemistry 7

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

4 Conclusion

-e optimized analytical methods were confirmed to beprecise and accurate for determination of TRG and TADbased on the simple economic assay -e methods wereapplied successfully on the pharmaceutical dosage formwith acceptable validation results Simultaneous de-termination for laboratory-prepared mixtures of TRG andTAD was achieved through manipulating their zero-orderfirst-order and ratio spectra-e developed methods shouldbe of interest to the analysts in the area of drug control andcan be used by QC laboratories

Conflicts of Interest

-e authors declare that they have no conflicts of interest

References

[1] R N Kushwaha W Haq and S B Katti ldquoSixteen-years ofclinically relevant dipeptidyl peptidase-IV (DPP-IV) in-hibitors for treatment of type-2 diabetes a perspectiverdquoCurrent Medicinal Chemistry vol 21 no 35 pp 4013ndash40452014

[2] D Stoimenis T Karagiannis A Katsoula et al ldquoOnce-weeklydipeptidyl peptidase-4 inhibitors for type 2 diabetes a sys-tematic review and meta-analysisrdquo Expert Opinion on Phar-macotherapy vol 18 no 9 pp 843ndash851 2017

[3] N Harada and N Inagaki ldquoOnce-weekly DPP-4 inhibitorrdquoNihon Rinsho Japanese Journal of Clinical Medicine vol 73no 12 pp 2096ndash2102 2015

[4] K Kaku ldquoSafety evaluation of trelagliptin in the treatment ofJapanese type 2 diabetes mellitus patientsrdquo Expert Opinion onDrug Safety vol 16 no 11 pp 1313ndash1322 2017

[5] K McKeage ldquoTrelagliptin first global approvalrdquo Drugsvol 75 no 10 pp 1161ndash1164 2015

[6] K Kaku ldquoFirst novel once-weekly DPP-4 inhibitor trela-gliptin for the treatment of type 2 diabetes mellitusrdquo ExpertOpinion on Pharmacotherapy vol 16 no 16 pp 2539ndash25472015

[7] J Yang S P Zhan and H Y Zhang ldquoClinical applicationreview of the novel once-weekly DPP-4 inhibitor trelagliptinin the treatment of type 2 diabetesrdquo Chinese Journal of NewDrugs vol 26 no 2 pp 145ndash150 2017

[8] M Murakami N Hirahara H Morita and S Sasaki ldquoEfficacyand safety of trelagliptin a once-weekly dipeptidyl peptidase-4(DPP-4) inhibitor a non-inferiority study in switching fromdaily DPP-4 inhibitor for the treatment of type 2 diabetespatientsrdquo Journal of the Japan Diabetes Society vol 60 no 3pp 222ndash228 2017

[9] C E Grimshaw A Jennings R Kamran et al ldquoTrelagliptin(syr-472 Zafatek) novel once-weekly treatment for type 2diabetes inhibits dipeptidyl peptidase-4 (dpp-4) via a non-covalent mechanismrdquo PLoS One vol 11 no 6 Article ID0157509 2016

[10] X Hu T Lan Z Chen et al ldquoA rapid and sensitive UHPLC-MSMS assay for the determination of trelagliptin in ratplasma and its application to a pharmacokinetic studyrdquoJournal of Chromatography B Analytical Technologies in theBiomedical and Life Sciences vol 1033-1034 pp 166ndash171 2016

[11] Q Wang X Chen C Zhang et al ldquoDetermination of theenantiomeric purity of trelagliptin by pre-column de-rivatization and liquid chromatography on a chiral stationary

phaserdquo Chromatographia vol 78 no 21-22 pp 1395ndash14002015

[12] H Zhang L Sun L Zou et al ldquoIdentification character-ization and HPLC quantification of process-related impuritiesin trelagliptin succinate bulk drug six identified as newcompoundsrdquo Journal of Pharmaceutical and BiomedicalAnalysis vol 128 pp 18ndash27 2016

[13] S Deng Z Li J Jiang et al ldquoDetermination of relatedsubstances in trelagliptin succinate by RP-HPLC and iden-tification of impurities from acid degradation by LC-MSMSrdquoChinese Journal of New Drugs vol 25 no 2 pp 226ndash231 2016

[14] International Conference on Harmonization (ICH) Q2BValidation of Analytical Procedures Methodology 62 US FDAFederal Register Washington DC USA 1997

Journal of Analytical Methods in Chemistry 7

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

TribologyAdvances in

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal ofInternational Journal ofPhotoenergy

Hindawiwwwhindawicom Volume 2018

Journal of

Chemistry

Hindawiwwwhindawicom Volume 2018

Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom Volume 2018

Enzyme Research

Hindawiwwwhindawicom Volume 2018

Journal of

SpectroscopyAnalytical ChemistryInternational Journal of

Hindawiwwwhindawicom Volume 2018

MaterialsJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International Electrochemistry

International Journal of

Hindawiwwwhindawicom Volume 2018

Na

nom

ate

ria

ls

Hindawiwwwhindawicom Volume 2018

Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom