Novel imaging method to quantify stratum corneum in dermatopharmacokinetic studies

Area of Science:

• Dermatology
• Biomedical Engineering
• Pharmacokinetics

Background:

• Stratum corneum (SC) quantification is crucial for topical bioequivalence studies.
• Accurate SC measurement informs drug concentration profiles and relative SC positioning.
• Established methods like weighing and UV pseudo-absorption have limitations.

Purpose of the Study:

• To introduce and evaluate a novel imaging method for quantifying SC on tape strips.
• To compare the performance of the imaging method against weighing and UV pseudo-absorption.
• To assess precision, signal-to-noise ratio, sample size, and speed of SC quantification techniques.

Main Methods:

• Three methods (weighing, UV pseudo-absorption, imaging) were used to measure SC on tape strips.
• Six SC tape strips were measured 15 times by each method.
• Correlations were examined using 600 tape strips assayed by each method.

Main Results:

• Weighing showed low precision and signal-to-noise ratio, and was slow.
• UV pseudo-absorption offered high precision and speed but analyzed only a fraction of SC, susceptible to inhomogeneity.
• The novel imaging method demonstrated high precision, excellent signal-to-noise ratio, analyzed the entire SC sample, and was rapid.

Conclusions:

• The novel imaging method offers significant advantages over established techniques for SC quantification.
• This imaging approach is precise, rapid, and robust against SC sample inhomogeneity.
• Potential for automated scanning and further image analysis enhances its utility in bioequivalence studies.