Lidocaine Paper Showcases Dermal Bioanalysis Expertise
AIT Bioscience and Teva Pharmaceuticals share their sensitive bioanalytical method for the measurement of lidocaine and a key metabolite from transdermal application in the Journal of Chromatography B. Those that contributed to this bioanalytical method include Qian Li, Tobias Magers, Brad King, Brian J. Engel, Ray Bakhtiar, Charisse Green and Ronald Shoup.
The featured methods detect lidocaine and its key metabolite, 2,6-dimethylaniline (2,6-DMA) in minipig plasma with sensitivities of 25 pg/mL and 200 pg/mL, respectively. Lidocaine levels for skin tissue biopsies and dermal tape strips (measuring stratum corneum concentrations) achieved sensitivities of 15 ng/gm tissue and 5 ng/tape. These quantitation limits were approximately 7-fold lower than previously reported for lidocaine and 3-fold lower for 2,6-DMA.
Key features of the lidocaine methods included solid phase extraction using mixed-mode microelution for plasma samples and the Waters HSS T3 UHPLC column to provide the necessary retention for this small, polar analyte. The 2,6-DMA methods featured ultrafiltration and derivatization to improve sensitivity for tissue samples.