Presented at the Advisory Committee for Pharmaceutical Science meeting on March 12, 2003 by Lucinda...
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Transcript of Presented at the Advisory Committee for Pharmaceutical Science meeting on March 12, 2003 by Lucinda...
Presented at the Advisory Committee for Pharmaceutical Science
meeting on March 12, 2003by
Lucinda Buhse, Ph.D.
Topical Drug Nomenclature
Objective: To establish a scientific basis for a systematic and coherent classification of dosage forms for topical drugs.
Working Group (ONDC/OGD/DPA): Cindy Buhse, Gil Jong Kang, Saleh Turujman, Mamta Gautam Basak, Chi Wan Chen
DPA Laboratory Team: Dick Kolinski, Nick Westenberger, Anna Wokovich, Jack Spencer
Current FDA Definitions
•Cream: A semisolid dosage form containing one or more drug substances dissolved or dispersed in a suitable base.
•Gel: A semisolid system consisting of either suspensions made up of small inorganic particles or large organic molecules interpenetrated by a liquid.
•Lotion: "The term lotion" has been used to categorize many topical suspensions, solutions and emulsions intended for application to the skin.
•Ointment: A semisolid preparation intended for external application to the skin or mucous membranes.
What are the distinguishing properties?
Physico-chemical• Viscosity
• Loss on Drying (LOD)
• Specific Gravity
• Surface Tension
• Water Solubility
• Water Absorption
• Drying Properties
• Thermogravimetric Analysis (TGA)
Chemical•Base Composition
Physical Properties•Appearance•Feel•Microscopy
Appearance•Clear, translucent or opaque
•viscous
•Greasy vs. non-greasy•Cooling sensation
Feel
Physical Properties
Microscopy - 400x
No Peak
Soft Peak Stiff Peak
Creams and Lotions: Multivariate Analysis of Selected Physico-chemical Properties
Viscosity is potentially a significant variable.
Scores Loadings
Lotions Creams
Viscosity Measurements of Selected Topical Products
0
25,000
50,000
75,000
100,000
125,000
150,000
175,000
200,000
Selected Products
Vis
cosi
ty (
cp)
Lotions
Creams
30,000 cp
Lotions are pourable (viscosity <30,000 cp at 5 rpm and 25ºC).
Viscosity of Selected Topical Products
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
1,800,000
2,000,000
Selected Products
Vis
cosi
ty (
cp)
CreamsOintments
Ointments <20% and Lotions >50%.
%Loss on Drying for Selected Topical Products
0
20
40
60
80
100
Selected Products
% L
oss
on
Dry
ing
LotionsCreamsOintments
Chemical Composition of Selected Topical Products
0
20
40
60
80
100
Selected Products
% h
ydro
carb
on a
nd
pol
yeth
ylen
e gl
ycol
Lotions
Creams
Ointments
Ointments have %hydrocarbon or Polyethylene Glycols >50%.
Chemical Composition (%) vs. Loss on Drying (%)
0
20
40
60
80
100
0 20 40 60 80 100
%LOD
% h
ydro
carb
on a
nd
pol
yeth
ylen
e gl
ycol
Lotions
Creams
Ointments
Common Characteristics of Most Marketed Gels
• Viscosity: low (10,000 - 70,000 cp)
• Loss on Drying : high (70-99%)
• Solubility : water soluble
• Water Absorption : no specific trend
• Drying Properties : no specific trend
• Thermogravimetric Analysis : fewer transitions
• Composition : contains gelling agents (carbomer)
• Appearance : clear
• Feel : non greasy, cooling
• Microscopy : no specific trend
0.00 100.00 200.00 300.00 400.00 500.00Temp [C]
0.00
20.00
40.00
60.00
80.00
100.00
%TGA
cream
cream cream
cream
gel
gel
Thermal Analysis - TGA"Drug B"
Gel formulations have fewer transitions than the creams.
0.00 100.00 200.00 300.00 400.00 500.00Temp [C]
0.00
25.00
50.00
75.00
100.00
%TGA
lotion
cream
gel
Thermal Analysis - TGA"Drug C"
Thermogravimetric Analysis of Selected Products
Drug B Drug CCream
Cream
Cream
Cream
Gel
Gel
Lotion
Cream
Gel