Modeling Temperature-Dependent Dermal Absorption and Clearance for Transdermal and Topical Drug Applications

Area of Science:

• Pharmacology
• Biophysics
• Computational Biology

Background:

• Transdermal drug delivery systems (TDS) offer a non-invasive route for systemic drug administration.
• Skin temperature is a critical factor influencing drug absorption and clearance kinetics.
• Understanding these thermal effects is crucial for optimizing TDS efficacy and safety.

Purpose of the Study:

• To develop and validate a computational model simulating heat and mass transport for transdermal drug delivery.
• To quantify the impact of elevated skin temperatures on dermal absorption and clearance.
• To assess the model's ability to predict in vitro and in vivo pharmacokinetics of nicotine TDS.

Main Methods:

• Development of a simultaneous heat and mass transport computational model.
• Validation using in vitro and in vivo human skin data for nicotine TDS.
• Analysis of temperature-dependent diffusion and dermal clearance mechanisms.
• Pharmacokinetic simulations using a two-compartment model.

Main Results:

• A 10°C increase in skin temperature approximately doubled nicotine absorption.
• The stratum corneum acts as the primary diffusion barrier, with an activation energy of 50-65 kJ/mol.
• Dermal capillaries efficiently clear nicotine at both normal and elevated temperatures.
• The model accurately predicted in vitro permeation and in vivo pharmacokinetics.

Conclusions:

• The developed computational model effectively describes transdermal nicotine delivery under varying skin temperatures.
• Elevated skin temperatures enhance dermal absorption, necessitating careful consideration in TDS application.
• The model provides a valuable tool for predicting TDS performance and optimizing drug delivery strategies.