2. Article on BA&BE

8/2/2019 2. Article on BA&BE

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Bioavailability and Bioequivalence Studies: Regulatory Aspects

Nitin, Parkash Ved, Bansal Nitin, Khar K Roop

Department of Pharmaceutics, B.S. Anangpuria Institute of Pharmacy, Ballabgarh- Sohna Road, Alampur, Faridabad, Haryana

Keywords: CDSCO, BA/BE, GCP.

Abbreviations: CDSCO-Central Drugs Standard Control Organisation, BA/BE - Bioavailability and Bioequivalence,

GCP- Good Clinical Practices.

Introduction:

Central Drugs Standard Control Organisation with Drugs & Cosmetics Act 1945 Schedule Y provides the guidelines for

performing the bioavailability and bioequivalence studies rules and regulations to ensure the uniformity in standards of quality,

safety and efficacy of the pharmaceutical products. Reasonable assurance has to be provided that various products, containing

same ingredients, marketed by different licensees, are clinically equivalent and interchangeable. According to CDSCO

Bioequivalence studies should be conducted for the comparison of two medicinal products containing the s ame active

substance. The studies should provide an objective means of critically assessing the possibility of alternative use of them. Two

products markets by different licensees, containing same active ingredient(s), must be shown to be therapeutically equivalent to

one another in order to be considered interchangeable. As BA and BE information has been determined to have practical and

public health value for pharmaceutical sponsors, for regulatory agencies, and for patients and practitioners. The purpose of this

article is to review the Regulatory Aspects to measure BA and establish BE based on recent draft and final guidance issued by the

Central Drugs Standard Control Organisation (CDSCO), Drugs & Cosmetic Act 1945 Schedule Y, Ministry of Health and Family

Welfare, GLP and the Ethical Guidelines for Biomedical Research on Human Participants (Indian Council of Medical Research,

New Delhi 2006).

Definitions:

Bioavailability- Bioavailability is a measure of the rate and extent of absorption of the active form or forms of a drug from itsformulation as reflected by the concentration - time curve of the administered drug in systemic circulation.

Bioequivalence- Two formulations of a drug are said to be bioequivalent if the rate and extent to which the drug reaches the

systemic action after administration of their respective formulations are statistically comparable. In general, two products may

be said to be bioequivalent if 90% Westlakes confidence interval for Cmax, Tmax, mean AUC (0-t) is within 20% of that of thereference product. The margin may be reduced to 10% for drugs with a very low therapeutic index, such as anti-arrhythmic,

antiepileptic and anticoagulant drugs.

Pharmaceutical Equivalence- "Pharmaceutical equivalents" mean drug products that contain identical amounts of the identical

active drug ingredient, i.e., the same salt or ester of the same drug, in identical dosage forms, but do not necessarily contain the

same ingredients, and that meet the identical compendial or other applicable standard of identity, strength, quality and purity,

including potency and where applicable, content uniformity, disintegration time and/or dissolution rates.

Therapeutic Equivalent- A medicinal product is therapeutically equivalent with another product if it contains the same active

substance or therapeutic moiety and, when administered to the same individual, shows the same efficacy and toxicity as that

product, whose efficacy and safety has been established.

Abstract

Bioavailability and/or bioequivalence study plays a vital role during period of drug development for both new drug products

and their generic equivalents. The methods involves in conduction of bioequivalence studies that bioavailability should be

compared between innovators and generic products. If this is not feasible then pharmacological effects supporting efficacy

or therapeutic effectiveness should be compared. This article reviews the regulatory aspects of bioavailability and

bioequivalence studies and provides CDSCO's recommendations for drug sponsors who intend to establish bioavailability

and/or demonstrate bioequivalence for their pharmaceutical products during the developmental process or after approval.

These guidelines describe the principle of procedures for bioequivalence studies of generic products. Finally, it concludes

several approaches to assess Bioequivalence; each regulatory authority has its own regulations for conducting BA/BE

studies before approving generic products for marketing. Thus, there is a greater need to harmonize the regulatory

environment for bioequivalence assessment practically,so that the drug product marketed in different parts and regions of

country.


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Cmax- This is the maximum drug concentration achieved in systemic circulation following drug administration.

Tmax- It is the time required to achieve maximum drug concentration in systemic circulation.

AUC0-t - Area under the plasma concentration - time curve from 0 h to the last quantifiable concentration to be calculated using

the trapezoidal rule

AUC0- - Area under the plasma concentration - time curve, from zero to infinity to be calculated as the sum of AUC0-t plus the

ratio of the last measurable concentration to the elimination rate constant

Dissolution- Dissolution is defined as the process by which a drug substance from a dosage form dissolves in a dissolution

medium to yield a solution.

Methodology to Conduct Bioequivalence Studies

Following are the important sequential steps for undertaking a bioequivalence study:

1. Request letter from the sponsor to the center to undertake a bioequivalence study on a product with relevant details.2. Consent letter by the bioequivalence center along with the checklist for the information to be provided by the sponsor.3. Letter with quotations and other formalities from the center to the sponsor.4. Protocol of the study prepared by the clinical pharmacologist and approved by the Ethical Committee to be forwarded to

the sponsor.

5. Consent letter and the protocol to be forwarded by the sponsor to the Drug Controller (India) for approval6. Approval letter from the Drug Controller (India) for conducting the bioequivalence study under the supervision of the chief

investigator at the bioequivalence center.

7. Letter from the sponsor to the bioequivalence center along with the copy of the approval letter from the Drugs Controller(India) requesting commencement of the study. The sponsor should provide all the information as per the checklist in item

2.

8. The study is planned by the center on screened healthy male volunteers whose laboratory investigations should be carriedout within one month prior to the commencement of the study.

9. Volunteers should be requested to report at the center at least 12 hrs before the study commences and should not beallowed to smoke or to take tea, beverages, alcohol, etc. during the study period.

10. Informed written consent should be obtained from volunteers and should be countersigned by witness.11. The study should commence at a predetermined time and must be conducted strictly according to the approved protocol.

Activity record should be filled in during the study.

12. The volunteers participating in the study should be asked personally for any symptoms or side effects which should then berecorded in the record sheet. Do you have any complaints?

13. Plasma/Serum samples should be frozen and stored at 20oC. For light sensitive drugs, vials should be covered. Theplasma/serum samples should be properly coded and labeled.

14. Drug analysis from the plasma/serum samples should be carried out by a previously validated analytical method, by anassayist from whom the name the product related to any sample is concealed by means of a suitable coding method.

After an appropriate washout period mentioned in the protocol, the crossover study should be carried out in a similarfashion. The bioavailability of the test formulation should be compared with that of the standard formulation and the

data on Cmax, Tmax, and AUC should be statistically analyzed. Dissolution data should be supplied by the sponsor on both the test and the standard preparations to the

bioequivalence center.

In-vitro dissolution studies are required where bioequivalence is not applicable e.g. anti-cancer drugs, drugs which aresystemically not absorbed, etc.

The report should be certified by the chief investigator, medical supervisor and the clinical pharmacologist and thensubmitted to the sponsor. An office copy of the report along with the raw data should be preserved up to 3 years from

the date of completion of the study at the bioequivalence center.

In-vivo Studies RegulationsPerson Responsible-The study protocol shall contain the following elements :The names of the principal investigator(s), other persons

responsible for conducting the study, and the names of the laboratory and the clinical pharmacology unit wherethe study will be conducted, should be mentioned. Complete official address of the premises of the laboratory andcontact phone numbers of the person in-charge of the study, with time for contact (in case of more than onephone numbers), should also be mentioned.The name of the sponsor and / or other person responsible for monitoring the study should be mentioned alongwith the complete official as well as residential addresses and phone numbers with contact times.


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Ethical Considerations-

All studies shall be conducted in accordance with the Ethical Guidelines for Biomedical Research on Human Participants

(Indian Council of Medical Research, New Delhi 2006).

There should be an ethical committee to approve the study and ensure that the study is carried out as perscientific and ethical norms. The ethical committee should be consist of qualified personnel including at least aclinical pharmacologist, a consultant physician, a social worker and a person with legal background. Sufficient andrelevant data on animal studies and human studies should be made available to the ethical committee.If for any reason, the approved protocol need amendments, the amended protocol should be approved by theethical committee and the Drugs Controller (India). Finally, the amended and approved protocol should besubmitted with the report.If the formulations under study, are likely to adversely affect the health of the volunteers, e.g. anticancer drugs,oral hypoglycemic drugs, etc., healthy volunteers should not be enrolled in the study. Patients should be enrolledin such cases. An informed and written consent form of the volunteer must be obtained and kept on record. Theparticipating volunteers should be provided with full information about the study in a language understandable tothem.

The information to the volunteer should include:a. Description of the drugb. Procedure of the study, i.e. mode of administration, number of blood samples, collection of any biological

specimen.c. Description of possible risks and benefits involved, if any, and the facilities available to tackle them.d. Right to opt out of the study without assigning any reason and without any liability .Study Design-Appropriate study design such as :

a. Single dose, randomize , two period, two treatment, complete crossoverb. Latin square design to be used for comparing three formulationsc. Balanced incomplete block (BIB) design in case of more three than formulationsd. Wash out period between any two subsequent treatments should not be less than 5 times of the reported

value of elimination half life (based on intravenous data) between the two treatments.

Healthy Volunteers-Number of volunteers: 12 normal, healthy adult male volunteers.

Inclusion criteria:a. Adult healthy male between age of 18 and 50 years.b. Height and weight according to the tables published by the LIC of India. A maximum variation of 10% on the

either side is permissible.c. The following hematological and other parameters should be within normal limits for those specific age, weight

and healthy combinations :(i) Complete blood count (Total and differential count)(ii) ESR- Erythrocyte Sedimentation Rate(iii) Liver function test

SGOT- Serum Glutamic Oxaloacetic Transaminase SGPT- Serum Glutamic Pyruvic Transaminase Serum bilirubin (direct and indirect) Serum alkaline phosphates Serum creatinine

(iv) Blood sugar : fasting, postprandial(v) Urine : routine and microscopic(vi) Australia antigen.(vii) HIV antigen

d. No abnormality on clinical examinatione. No history of any illness in past 8 weeks

Exclusion criteria:a. Consumption of tobacco in any formb. Addiction to alcohol or history of any drug abusec. History of kidney or liver dysfunctiond. History of jaundice in the past 6 monthse. History of drug allergy to the test drug or any chemically similar to the drug under investigationf. Administration / intake of any prescription or OTC medication for 2 weeks before the studyg. Patient suffering from any chronic illness such as arthritis , asthma etch. Subject suffering from any psychiatric (acute or chronic) illnessi. Participation in any bioavailability / bioequivalence study in the past 12 weeksj. Intake of barbiturates or any enzyme inducing drug in the past 3 monthsk. HIV positive volunteers


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Conduct of the Study

a. All the volunteers should be admitted in the ward / bioavailability center atleast 12 hours prior to theadministration of the study drug dosage form. They should be housed for adequate time.

b. Time of administration of medication (test and reference) should be in the morning and the same time shouldstrictly adhered during the entire study

c. Tea, coffee and caffeine / xanthine - containing beverages and food should not be allowed during each phaseof the study/

d. All volunteers should fast for 12 hours predosing and continue to fast for at least 2 hours postdosing or foradequate time after dosing.

e. Uniform and identical meals should be provided at identical times to all volunteer from the time they areadmitted and till the time they are housed.

f. A precise work schedule should be prepared in advance and explained to the volunteers.g. The exact time of drug administration, sample collection and meals should be strictly adhered to and the

actual time of each activity should be properly and accurately documented.h. Test tubes/vials required for sample collection should be elaborately labeled in advance and kept ready.i. Standard quantity of water (one glass : 200 ml) should be allowed for proper ingestion of the drug.j. The investigator will provide the medication to the volunteers and the volunteers must consume the drug in

the presence of the investigator.k. After ingestion of the medication, the volunteers should rest in supine position at least for 2 hours to ensure

proper gastric emptying. Subsequently, although the volunteers are ambulatory, any strenuous physical ormental activity should not be permitted.

l.

Blood samples should be collected by using disposable needles, syringes , etc.m. Multiple blood sample collection should be done by using disposable in dwelling venous canulae / catheters inorder to avoid repeated venupuncture.

n. Care should be taken not to withdraw more than 250 ml of blood per volunteer in one month.o. An attending physician will be present at all times to oversee the conduct of the investigation as well as to

answer any queries by the volunteers.p. Emergency medical equipment and support services will be available and accessible throughout the

investigation.

Blood Sampling

Adequate number (at least three) of venous blood samples should be collected during the absorption phase andshould be well spread over the expected duration of the absorption phase.a. At least 3 blood samples should be collected around the expected time of peak blood levels. This can be made

possible by adjusting 1 to 2 points each from absorption points (last ones) and distribution points (earlierones) as near the Cmax as possible. Its timing should be decided on the basis of the published information. Inthe absence of any published information a pilot study with limited volunteers may be performed earlier to theactual bioequivalence study.

b. Sampling container should be sterilize using dry heat. While transferring the sample from the syringe , theneedle should be removed and the syringe should be slowly emptied along with the sides of the container.Should it be mandatory to use presterilized instruments.?

c. The sampling container should contain an adequate amount of anticoagulant. The anticoagulant (in case ofplasma) should be chemically compatible with the drug and should not increase the volume of blood samplestored in the container.

d. The separation of plasma or serum should be done immediately following the collection and it should be storedin two identical containers with identical labels.

e. Once separated the plasma, serum or the biological fluid collected, should be immediately frozen to 10oc to 20oc till the time of analysis. Adequate precautions should be taken in case of light- sensitive drugs.

f. The analysis should be performed immediately if the substance (drug) is known to degrade on storaging.Analytical Method

Details of the analytical method intended to be used for the analysis of the biological sample should be included inthe protocol.

Evaluation Parameters

The following pharmacokinetic parameters from blood/serum concentration time data should be determined foreach volunteer in each treatment :a. Cmaxb. Tmaxc. AUC : both AUC o-t and AUC 0-All the above parameters should be tabulated for each volunteer for both the treatments to permit the calculationof mean, standard deviation and coefficient of variation.


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Statistical Analysis

a. The methods/techniques to be used should be decided and mentioned in the protocol before the study beginsb. Whenever user-defined software is used for analysis, it should be validated.c. When the analysis is performed manually, all the results of intermediate steps should be properly recorded.

In-vitro Studies Regulations

In certain situations a comparative in vitro dissolution study may be sufficient to demonstrate equivalence between two drugproducts. The test methodology adopted should be in line with the pharmacopoeial requirements unless those requirements are

shown to be unsatisfactory.

Dissolution studies should generally be carried out under mild agitation conditions at 370.5C and at physiologically relevant

pH. More than one batch of each formulation should be tested. Comparative dissolution profiles, rather than single point

dissolution test data, should be generated. The design should include:

I. Individually testing of at least twelve dosage units (e.g., tablets, capsules) of each batch. Mean and individual resultsshould be reported along with their standard deviations or standard errors.

II. Measuring the percentage of nominal content released at a number of suitably spaced time points to provide a profilefor each batch, e.g. at 10, 20 and 30 minutes or as appropriate to achieve virtually complete dissolution.

III. Determining the dissolution profile in at least three aqueous media covering the pH range of 1.0 to 6.8 or in caseswhere considered necessary, pH range of 1.0 to 8.0.

IV.

Conducting the tests on each batch using the same apparatus and, if possible, on the same or consecutive days.

Comparisons of the dissolution profiles may be made by any of the established Model-independent or model-dependent

methods.

In following circumstances equivalence may be assessed by the use ofin vitro dissolution testing:A. Drugs for which the applicant provides data to substantiate all of the following:i. highest dose strength is soluble in 250 ml of an aqueous media over the pH range of 1-7.5 at 37Cii. at least 90% of the administered oral dose is absorbed on mass balance determination or in comparison to an

intravenous reference dose

iii. speed of dissolution as demonstrated by more than 80% dissolution within 15 minutes at 37C using IP apparatus1, at 50 rpm or IP apparatus 2, At 100 rpm in a volume of 900 ml or less in each of the following media:

1. 0.1 N hydrochloric acid or artificial gastric juice (without enzymes)

2. a pH 4.5 buffer

3. a pH 6.8 buffer or artificial intestinal juice (without enzymes)

B. Different strengths of the drug manufactured by the same manufacturer, where all of the following criteria are fulfilled:

i. the qualitative composition between the strengths is essentially the same;ii. the ratio of active ingredients and excipients between the strengths is essentially the same, or, in the case of small

strengths, the ratio between the excipients is the same;

iii. the method of manufacture is essentially the same;iv. an appropriate equivalence study has been performed on at least one of the strengths of the formulation (usually

the highest strength unless a lower strength is chosen for reasons of safety); and

v. In case of systemic availability - pharmacokinetics have been shown to be linear over the therapeutic dose range.In vitro dissolution testing may also be suitable to confirm unchanged product quality and performance.

Facilities for conducting Bioavailability And/or Bioequivalence Studies

Legal identity:

The organization, conducting the bioequivalence / bioavailability studies, or the parent organization to which it belongs, must be

a legally constituted body with appropriate statutory registrations.

Impartiality, confidentiality, independence and integrity:

The organization shall:

a. have managerial staff with the authority and the resources needed to discharge their duties.

b. have arrangements to ensure that its personnel are free from any commercial, financial and other pressures which might

adversely affect the quality of their work.

c. be organized in such a way that confidence in its independence of judgment and integrity is maintained at all times.

d. have documented policies and procedures, where relevant, to ensure the protection of its spo nsors confidential information

and proprietary rights.


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e. not engage in any activity that may jeopardize the trust in its independence of judgment and integrity

f. have documented policies and procedures for the safety of human rights and the use of human subjects in research consistent

with Schedule Y (refer Drugs & Cosmetics Act and Rules) and GCP Guidelines

g. have documented policies and procedures for scientific integrity including procedures dealing with and reporting possible

scientific misconduct.

Organization and management:

The study site organization must include the following:

a. An Investigator who has the overall responsibility to provide of the human subjects. The Investigator(s) should possess

appropriate medical qualifications and relevant experience for conducting pharmacokinetic studies.

b. The site should have identified adequately qualified and trained personnel to perform the following functions:

i. Clinical Pharmacological Unit (CPU) management

ii. Analytical laboratory management

iv. Data handling and interpretationv. Documentation and report preparationvi. Quality assurance of all operations in the centre

Documented Standard Operating Procedures

The center shall establish and maintain a quality system appropriate to the type, range and volume of its activities. All

operations at the site must be conducted as per the authorized and documented standard operating procedures. These

documented procedures should be available to the respective personnel for ready reference. The procedures covered must

include those that ensure compliance with all aspects of:a. GCP Guidelines

b. Good laboratory practice guidelines issued by Ministry of Health & Family Welfare.

A partial list of procedures for which documented standard operating procedures should be available includes:

a. maintenance of working standards (pure substances) and respective documentation.

b. withdrawal, storage and handling of biological samples.

c. maintenance, calibration and validation of instruments.

d. managing medical as well as non-medical emergency situations

e. handling of biological fluids

f. managing laboratory hazards

g. disposal procedures for clinical samples and laboratory wastes

h. documentation of clinical pharmacology unit observations, volunteer data and analytical datai. obtaining informed consent from volunteers

j. volunteer screening and recruitment and management of ineligible volunteers

k. volunteer recycling (using the same volunteer for more than one study

l. randomization code management

m. study subject management at the site (including check-in and check-out procedures)

n. recording and reporting protocol deviations

o. monitoring and quality assurance wherever possible, disposable (sterile, wherever applicable) medical devices must

be used for making subject interventions.

If services of a laboratory or a facility other than those available at the site (whether with in India or outside the country) are to

be availed its/their name(s), address(s) and specific services to be used should be documented.

Clinical Pharmacological UnitIt must have adequate space and facilities to house at least 16 volunteers.

Adequate area must be provided for dining and recreation of volunteers, separate from their sleeping area.

Additional space and facilities should also be provided for the following:

a. Office and administrative functions

b. Sample collection and storage

c. Control sample storage

d. Wet chemical laboratory

e. Instrumental Laboratory

f. Library

g. Documentation archival room

h. Facility for washing, cleaning and Toilets

i. Microbiological laboratory (Optional)

j. Radio Immune Assay room (optional)

MAINTENANCE OF RECORDS OF BA/BE STUDIES


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All records of in vivo or in vitro tests conducted on any marketed batch of a drug product to assure that the product meets a

bioequivalence requirement shall be maintained by the Sponsor for at least 2 years after the expiration date of the batch and

submitted to CDSCO on request.

RETENTION OF BA/BE SAMPLES

All samples of test and reference drug products used in bioavailability / bioequivalence study should be retained by the

organization carrying out the bioavailability / bioequivalence study for a period of three years after the conduct of the study or

one year after the expiry of the drug, whichever is earlier. The study sponsor and/or drug manufacturer should provide to the

testing facility batches of the test and reference drug products in such a manner that the reserve samples can be selected

randomly. This is to ensure that the samples are in fact representative of the batches provided by the study sponsor and/or

Drug manufacturer and that they are retained in their original containers. Each reserve sample should consist of a quantity

sufficient to carry out twice all the in-vitro and in-vivo tests required during bioavailability / bioequivalence study. The reserve

sample should be stored under conditions consistent with product labeling and in an area segregated from the area where

testing is conducted and with access limited to authorized personnel.

ConclusionRegulatory Authorities i.e.CDSCO, health ministry of India and Drugs & Cosmetics Act, 1945 (Amended 2005) provides

certain guidelines to ensure the safety and efficacy of new drugs and generic pharmaceutical products marketed in India. By

such guidelines authorities also provides the safety parameters to ensure the safety of the human volunteers participating in

such studies of BA / BE. These guidelines not only provides safety to the human volunteers but also gives directions to the

pharmaceutical industries to work with hurdle- free studies without compensating the safety of people. Bioequivalence studies

also reduce the demands of in-vivo studies by providing guidelines for the in-vitro studies which may compare with in-vivo data

in some cases.

References1. Guidelines for Bioavailability and Bioequivalence Studies, Central Drugs Standard Control Organisation, Directorate

General of Health Services, Ministry of Health & Family Welfare, Government of India, New Delhi, March 2005.

2. Guidance for industry Central Drugs Standard Control Organization, Ministry of Health, Govt. of India.3. Ethical Guidelines for Biomedical Research on Human Participants, Indian Counsil of Medical Research, New Delhi,

2006.

4. Draft Guidelines For Bioavailability/ Bioequivalence Studies fromhttp://cdsco.nic.in/html/be_document.htm5. Tamboli M. Asif, Todkar Pavan, Zope Priti and Sayyad F.J., An Overview on Bioequivalence: Regulatory Consideration

for Generic Drug Products, Journal of Bioequivalence & Bioavailability, Volume 2, issue 4, 2010.

6. Mei-Ling Chen, Shah Vinod, Patnaik Rabindra, Wallace Adams, Hussain Ajaz, Dale Conner, Mehta Mehul, HenryMalinowski, Lazor John, Shiew-Mei Huang, Don Hare, Lawrence Lesko, Douglas Sporn, and Roger Williams,

Bioavailability and Bioequivalence: An FDA Regulatory Overview, Pharmaceutical Research, Vol. 18, No. 12, December

2001.
http://cdsco.nic.in/html/be_document.htmhttp://cdsco.nic.in/html/be_document.htmhttp://cdsco.nic.in/html/be_document.htmhttp://cdsco.nic.in/html/be_document.htm

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