Confocal Raman analysis of a transdermal nicotine patch by a DXR2 Raman Microscope

Importance of the Topic

Transdermal patches offer a noninvasive and controlled approach to deliver active pharmaceutical ingredients through the skin into the bloodstream. Understanding the material composition and layer structure of these systems is essential for quality control, regulatory compliance, and optimizing drug release profiles.

Objectives and Study Overview

This study aimed to demonstrate how confocal Raman microscopy can be used to characterize the multilayer architecture of a commercially available nicotine transdermal patch without destroying the sample. Key goals included identifying each polymer layer, mapping the spatial distribution of nicotine within the patch, and evaluating layer thicknesses.

Methodology and Instrumentation

Raman confocal line and area depth profiling were performed on a Thermo Scientific DXR2 Raman Microscope. A 532 nm laser at 5 mW, a 50× objective, and a 25 µm confocal aperture were used. Z-profiling covered 220 µm depth with 5 µm steps (45 spectra), while X–Z mapping spanned 120 µm×245 µm with 350 spectra. Data acquisition and analysis employed the OMNIC for Dispersive Raman and OMNIC Atlμs software suites. Multicomponent identification used OMNIC Specta with a high-resolution polymer library and a patented search algorithm.