Proposed Definitions and Decision Tree for Topical Dosage Forms

1
Proposed Definitions and Decision Tree for
Topical Dosage Forms

• Advisory Committee for
• Pharmaceutical Science
• March 12, 2003
• Chi-wan Chen, Ph.D.
• Director, DNDCIII/ONDC/OPS
• CDER/FDA

2
Scope

• Dermatological application only
• Five topical dosage forms, i.e., lotion, gel,
  cream, ointment, paste, because the existing
  definitions are less than adequate and because
  they cannot readily distinguish between
• lotion vs cream
• Gel vs cream/lotion
• Ointment vs cream
• Paste vs ointment

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Gel

• A semisolid emulsion or suspension
• Contains a gelling agent in sufficient quantities
  to impart a 3-dimensional, cross-linked matrix
• Provides a cooling sensation when applied to the
  skin
• Usually translucent and non-greasy

4
Paste

• A semisolid suspension
• Contains a large proportion (i.e., 20-50) of
  solids finely dispersed in an aqueous or fatty
  vehicle
• Opaque, viscous, greasy to mildly greasy
• Adheres well to the skin, forming a protective
  layer

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Lotion

• A liquid emulsion
• Generally contains a water-based vehicle with
  50 of volatiles
• Has sufficiently low viscosity that it may be
  poured
• Opaque and non-greasy
• Tends to evaporate rapidly with a cooling
  sensation when applied to the skin

6
Ointment

• A semisolid emulsion or suspension
• Generally contains 50 of hydrocarbons or PEGs
  as the vehicle and
• Opaque or translucent, viscous, greasy
• Tends not to evaporate or be absorbed when
  applied to the skin

7
Cream

• A semisolid emulsion or suspension
• Generally contains as the vehicle and/or 20 of volatiles
• Opaque, viscous, non-greasy to mildly greasy
• Tends to mostly evaporate or be absorbed when
  applied to the skin
• Can be hydrophilic or lipophilic

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Decision Tree

• Intended to be a tool to help determine the
  correct topical dosage form
• Includes several key tests based on NDA/ANDA data
  and FDA lab results

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Decision Tree
Topical d.f.
A topical dosage form for dermatological
application
What kind is it?
10
Test 1
Topical d.f.
Is it a liquid emulsion or a semisolid emulsion
or suspension?
Solution aerosol powder suspension
N
1
Y
2
3
5b
4

• If no, it is a solution, aerosol, powder, or
  suspension
• If yes, go to Test 2

5a
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Test 2
Topical d.f.
Does it contain sufficient quantities of a
gelling agent to form a 3D matrix?
Solution aerosol powder suspension
1
Y
N
2
3
Gel
5b
4

• If yes, it is a gel
• If no, go to Test 3

5a
12
Test 3
Topical d.f.
Does it contain a large proportion (20-50)
of dispersed solids?
Solution aerosol powder suspension
1
Y
2
3
Gel
Paste
N
5b
4

• If yes, it is a paste
• If no, go to Test 4

5a
13
Test 4
Topical d.f.
Does it contain 50 of volatiles (as measured
by LOD)?
Solution aerosol powder suspension
1
2
3
Gel
Paste
N
5b
4

• If yes, go to Test 5a
• If no, go to Test 5b

Y
5a
14
Test 5a
Topical d.f.
Is it a pourable liquid with a viscosity of 30,000 cps)?
Solution aerosol powder suspension
1
2
3
Gel
Paste
5b
4

• If yes, it is a lotion
• If no, it is a cream

Y
5a
Lotion
N
Cream
15
Test 5b
Topical d.f.
Does it contain (1) 50 of hydrocarbons or PEG
as the vehicle and (2) Solution aerosol powder suspension
1
2
3
Gel
Paste
Y
5b
4
Ointment

• If yes to both, it is an ointment
• If no to either or both, it is a cream

N
5a
Lotion
Cream