Revisiting techniques to evaluate drug permeation through skin

Area of Science:

• Dermatology
• Pharmaceutics
• Drug Delivery

Background:

• Drug permeation and retention in skin layers are critical for transdermal and topical drug delivery.
• This information is vital for optimizing drug formulations and predicting therapeutic efficacy.

Purpose of the Study:

• To review and discuss various methods for estimating drug/therapeutics in skin layers.
• To highlight the application of these techniques in formulation development for local and systemic effects.

Main Methods:

• Covers in vitro (diffusion techniques), ex vivo (isolated perfused skin models), and in vivo (dermato-pharmacokinetics, tape stripping, microdialysis) methods.
• Discusses the application of these techniques across different stages of formulation development.

Main Results:

• Various techniques exist to estimate drug levels in skin layers under different experimental conditions.
• These methods provide insights into drug permeation and retention, aiding formulation optimization.

Conclusions:

• Current methodologies require improvement, including standardization of protocols and regulatory guidelines.
• Utilizing multiple techniques for dermato-pharmacokinetics evaluation is essential for accurate assessment of formulation efficacy.
• Further research and development of alternative skin models are needed to enhance data reliability.