# Presentation: 451793

## Topical Dermatologic Dosage Forms and Vehicle Properties:  Issues and Opportunities

- Jonathan Wilkin, M.D.
- Director, Division of Dermatologic and
- Dental Drug Products, FDA

## Background I

- 		If it’s dry, wet it.
- 		If it’s wet, dry it.
- Paleodermatologic aphorism.

## Background II

- 	Originally, no “active” ingredient.
- 	Therapeutic choice based on physical and 			sensory properties.

## Background III

- In the 1800s
- “Active” ingredients began to be added
- Topical dosage formulations grouped under 		commonly used terms.

## Background IV

- Powder (crystals) for bath solution
- Colloid baths
- Bath oils (including bath tars)
- Solutions or suspensions for wet dressings and soaks
- Shake lotions - “shake” to disperse powders
- Creamy-type lotions - (w/o and o/w)
- Creams
- Ointments

## Background IV (cont’d)

- Pastes
- Solutions
- Tinctures
- Suspensions (shake lotions)
- Varnishes
- Powders

## Background V

- 		Later additions:
- 	  		Gels
- 	  		Foams
- 	  		Emollient creams

## Problems

- FDA and USP dosage forms insufficiently 	defined
- Manufacturers produce dosage form 		intergrades, e.g., between creams and 		lotions that resist classification

## Opportunities

- Creation of mutually exclusive definitions 	for dosage forms and consistent 		terminology
- Summary of relevant vehicle properties in 	the Description section of product 	labeling
- Provide clinically important information 	to health care providers choosing 	among topical dermatologic products

## Relevant Vehicle Properties

- Dosage form - a rough guide
- Description section -  specific information

## Examples of Potential, Relevant Vehicle Properties

- Viscosity - could be an ordinal classification       and nonlinear
- Spreadability  - spread value in mm2 in 10 minutes
- Wash and rub resistance
- Skin smoothness - time curve
- Usual appearance of product, incl. color
- Odor of product

## Examples of Potential, Relevant Vehicle Properties (cont’d)

- Permanence on skin surface - residue at 10 		    minutes
- Moisturization - TEWL time curve
- Volatilization - time curve

## Slide 14

## Slide 15

## Salka, Barry A.
Choosing emollients.
Cosmetics & Toiletries
112:101-106, 1997

- Choosing emollients.
- _Cosmetics_ _&_ _Toiletries_
- 112:101-106, 1997

## Vehicle Choice

- Important factor in patient compliance
- Prescribing physician needs relevant information:
-         well-defined dosage forms
-         description of relevant vehicle properties

## Impact on Stakeholders

- Innovators - more specific description of 		product may reduce generic competition
- Generics - better defined target leads to 		greater sameness of generic product
- Health care providers - better choice among 		products
- Patients - product acceptability improves 		compliance leading to better outcomes

## Looking Ahead

- 1.  Definitions and Classification of Topical 			Dermatologic Dosage Forms
- 	Need industry, academia, professional 			scientific societies, USP and FDA 			consensus

## 2.  Development of Consistent Methodology 	and Terminology to Describe Relevant 	Vehicle Properties (for Description 		Section of Labeling)

	Industry may already have the methods 		and terminology.  Industry must 			decide if this is desirable.  If so, 			they must be leaders in this effort.

- 	Industry may already have the methods 		and terminology.  Industry must 			decide if this is desirable.  If so, 			they must be leaders in this effort.