Methods for in vitro percutaneous absorption studies V: Permeation through damaged skin

Area of Science:

• Dermatology
• Pharmacokinetics
• Biophysics

Background:

• Transdermal drug delivery agents are sometimes applied to compromised skin barriers.
• Understanding how skin damage affects compound permeation is crucial for optimizing topical treatments.

Purpose of the Study:

• To compare the permeation of compounds through skin damaged by various methods.
• To investigate the relationship between the extent of skin damage and compound absorption.

Main Methods:

• Comparing compound permeation through skin damaged by cellophane tape stripping, needle abrasion, and UV irradiation.
• Utilizing both in vivo and in vitro techniques to assess penetration of cortisone and nicotinic acid.
• Evaluating the absorption of seven chemicals through abraded human and rat skin.

Main Results:

• Cellophane tape stripping of the stratum corneum maximally enhanced absorption.
• Multiple needle abrasions significantly increased water and compound permeation.
• In vivo UV irradiation damage mirrored in vitro abraded skin absorption for nicotinic acid.
• Increased absorption of chemicals correlated with their inherent poor skin absorption.

Conclusions:

• The stratum corneum is a primary barrier to topical compound absorption.
• The degree of skin damage directly influences the extent of compound permeation.
• The effectiveness of topical agents on damaged skin depends on the chemical properties of the applied compounds.