Raman Spectroscopic Tools to Probe the Skin-(Trans)dermal Formulation Interface

Area of Science:

• Pharmaceutical Sciences
• Biomedical Engineering
• Analytical Chemistry

Background:

• Topical and transdermal drug products are complex formulations requiring precise methods to assess drug delivery.
• Quantifying drug levels and kinetics within the skin is crucial for product development and efficacy.
• Minimally invasive techniques are sought to evaluate drug absorption and clearance into systemic circulation.

Purpose of the Study:

• To illustrate the application of confocal Raman microspectroscopy and imaging for analyzing topical and transdermal drug delivery.
• To elucidate chemical properties influencing drug transfer at the formulation-skin interface.
• To investigate drug product transformation, solubility changes, and skin absorption kinetics.

Main Methods:

• Confocal Raman microspectroscopy and imaging were employed to study drug delivery systems.
• Techniques included visualization, depth slicing, and profiling to analyze drug-skin interactions.
• The study focused on the chemical properties of the delivery system and skin, drug transformation, and absorption.

Main Results:

• Confocal Raman microspectroscopy provided insights into the chemical interactions at the formulation-skin interface.
• The method allowed visualization of drug product transformation and changes in active compound solubility post-application.
• Drug absorption into the skin and subsequent clearance into deeper layers were investigated.

Conclusions:

• Confocal Raman microspectroscopy offers valuable qualitative and semi-quantitative data on topical and transdermal drug product performance.
• The technique aids in understanding drug transfer, transformation, and skin penetration.
• This approach supports the improvement and optimization of topical and transdermal drug formulations.