Open-Label Adhesion Performance Studies of a New Lidocaine Topical System 1.8% versus Lidocaine Patches 5% and Lidocaine Medicated Plaster 5% in Healthy Subjects

Open-Label Adhesion Performance Study of a Prescription Lidocaine Topical System 1.8% versus Three Lidocaine-Containing Over-the-Counter Patches in Healthy Subjects

Purpose

Patients and Methods

Results

Conclusion

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

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.

Clinicaltrials.gov

NCT04784728.

Biorelevant In Vitro Skin Permeation Testing and In Vivo Pharmacokinetic Characterization of Lidocaine from a Nonaqueous Drug-in-Matrix Topical System

Recently, lidocaine topical systems utilizing nonaqueous matrices have been developed and provide efficient lidocaine delivery through the skin, such that lower concentrations of drug provide equivalent or greater drug delivery than drug-in-matrix hydrogel lidocaine patches. This study characterizes drug delivery from a nonaqueous lidocaine topical system with increasing drug load both in vitro and in vivo. Topical systems formulated with either 1.8% or 5.4% lidocaine were applied to healthy volunteers' backs (n = 15) for 12 h in a single-center, open-label, four-treatment, four-period crossover pharmacokinetic study. Subjects were dosed with either three 1.8% systems or one, two, or three 5.4% systems in each period. Blood was collected for up to 48 h, and plasma lidocaine levels were measured with a validated HPLC method. In parallel, human and mouse skin models characterized the in vitro skin permeation profile. The pharmacokinetic profile was linear between one, two, and three lidocaine 5.4% applications. Application of three lidocaine 1.8% systems (108 mg lidocaine) was bioequivalent to one lidocaine 5.4% system (108 mg lidocaine). Both topical systems remained well adhered to the skin and irritation was mild. The 5.4% system had approximately threefold higher skin permeability than the 1.8% system in the mouse and human skin models. The results indicate increasing the drug load by three times results in triple the drug delivery both in vivo and in vitro. The relationship between the in vitro permeation and in vivo absorption correlates and is nonlinear.