Quantitative chromatographic method development for residual lidocaine in topical systems and biological samples

Area of Science:

• Analytical Chemistry
• Pharmaceutical Sciences
• Pharmacokinetics

Background:

• Topical drug delivery systems require precise methods to quantify drug exposure and residues.
• Assessing systemic drug exposure and local residual drug is crucial for efficacy and safety evaluations.

Purpose of the Study:

• To develop and validate sensitive and efficient analytical methods for estimating drug levels from topical formulations.
• To quantify lidocaine content in commercial topical products and analyze its presence in human serum.

Main Methods:

• Liquid-liquid extraction was employed for lidocaine extraction from topical products.
• Ultra-high-performance liquid chromatography (UHPLC) was used for product analysis.
• Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for human serum sample analysis.

Main Results:

• The developed methods accurately quantified lidocaine in two commercial topical products (97.4-110.7% recovery).
• The LC-MS/MS method demonstrated successful analysis of lidocaine in human serum samples.
• Validation confirmed the sensitivity and efficiency of the analytical techniques.

Conclusions:

• The validated analytical methods are suitable for quantifying systemic drug exposure from topical systems.
• These methods are recommended for residual drug analysis in topical delivery systems.
• The study provides reliable tools for pharmacokinetic and safety assessments of topical lidocaine formulations.