A Randomized, Crossover, Adhesion Performance and Pharmacokinetic Study of a Lidocaine Topical System Under Conditions of Water Exposure in Healthy Subjects

Abstract

Purpose: This study compares the adhesion performance, pharmacokinetic profile, and safety of lidocaine topical system 1.8%, which is approved to treat postherpetic neuralgia, under conditions of swimming and showering versus normal conditions.

Patients and methods: This open-label, 3-period, 3-treatment crossover study randomized 24 healthy adults to receive one lidocaine topical system during each of three treatment periods; subjects either swam in a heated swimming pool for 15 minutes 4.0 hours post-product application (swimming), showered for 10 minutes 8.0 hours after product application (showering), or the product remained dry throughout the treatment period (normal conditions). The product was applied to the mid-upper back and was removed after 12 hours. The pharmacokinetic profile of each subject under water exposure conditions was compared to subjects under normal conditions. Skin irritation, adhesion, and adverse events were assessed.

Results: Twenty-four (24) subjects enrolled and 23 completed the study. Exposure to water resulted in lifting of the topical systems. There were two complete detachments, as well as seven occurrences of major lifting (more than 50% detached) after water exposure. The topical systems were immediately pressed down and/or reapplied after observing lifting and remained adhered to for the rest of the 12-hour application period. No clinically relevant differences in systemic absorption were observed under either showering or swimming conditions. The topical systems were well tolerated, with only mild adverse events, none leading to discontinuation.

Conclusion: These data show that while water exposure can cause the topical system to lift or detach, the lidocaine topical system 1.8% is capable of being reapplied and maintains adhesion for up to 12 hours of wear with no clinically significant changes in drug delivery.

Clinicaltrialsgov: NCT04784728.

Keywords: adhesion; lidocaine topical system; postherpetic neuralgia; water exposure.

Conflict of interest statement

Dr Patel and Dr Lissin are full-time employees of Scilex Pharmaceuticals Inc. Mr Vought was an employee of Scilex Pharmaceuticals Inc at the time the study was conducted. Dr. Greuber was an employee of Scilex Pharmaceuticals Inc. at the time the study was conducted and is currently with Regulatory and Strategic Development, Clinipace, Inc., Morrisville, NC, USA. Dr Charles Argoff reports personal fees from Scilex, BDSI, Biohaven, Nevro, Amgen, and Novartis; grants, personal fees from AbbVie, Teva, Lilly, and Flowonix; royalties for book publication from Elsevier, outside the submitted work. This article is the sole work of the authors; stated opinions or assertions do not reflect the opinions of employers or employee affiliates listed. The authors report no other conflicts of interest in this work.

© 2021 Vought et al.

Figures

Figure 1

Adhesion of lidocaine topical system 1.8% over time under swimming, showering, and normal conditions. Adhesion scores were evaluated at 0, 3, 4.5,7, 8.5 and 12 hours after application. The 4.5- and 8.5-hour time points were selected to obtain an assessment shortly after the water exposure activities had completed. Mean adhesion was >90% for all treatments at the end of 12-hour administration.

Figure 2

Mean plasma lidocaine concentration after application of one lidocaine topical system 1.8% vs time under swimming, showering, and normal conditions.