Understanding Formulation and Temperature Effects on Dermal Transport Kinetics by IVPT and Multiphysics Simulation

Area of Science:

• Dermal pharmacokinetics
• Topical drug delivery
• Multiphysics modeling

Background:

• Understanding topical product formulation effects on skin transport is complex.
• Environmental factors like temperature poorly understood in dermal absorption.
• In vitro permeation testing (IVPT) provides combined mechanistic process data.

Purpose of the Study:

• To investigate how formulation type and temperature influence oxybenzone transport kinetics in human skin.
• To develop and validate a multiphysics simulation model for predicting dermal absorption.

Main Methods:

• Evaluated two oxybenzone sunscreen formulations (cream, spray) using in vitro permeation testing (IVPT) in human skin.
• Assessed temperature effects by testing at 32°C and 37°C.
• Developed a multiphysics-based simulation model to compute drug flux.

Main Results:

• Significant differences in drug transport kinetics were observed between the cream and spray formulations.
• Environmental temperature markedly influenced the flux of oxybenzone.
• The multiphysical simulation model successfully reproduced experimental IVPT findings.
• Drug diffusion coefficient, influenced by temperature-dependent water content, was identified as dominant in transport kinetics.

Conclusions:

• Combined in vitro testing and simulation provide mechanistic insights into dermal absorption.
• Dissimilar topical product formulations exhibit distinct skin absorption profiles.
• Temperature is a critical factor affecting topical product efficacy and skin penetration.