Bioequivalence study of two lidocaine patches formulation in healthy Chinese subjects: the randomized, single-center, open-label, single-dose, 2-way 2-period crossover study

Abstract Background: (1) To evaluate the bioequivalence between test and reference formulations of lidocaine patches and to assess their pharmacokinetic (PK, C max and AUC) in healthy Chinese subjects. (2) To evaluate the noninferiority between test and reference formulations of lidocaine patches and to assess their average adhesion score in healthy Chinese subjects. (3) To evaluate the skin irritation and safety between test and reference formulations of lidocaine patches in healthy Chinese subjects. Method: A randomized, single-center, open-label, single-dose, 2-way 2-period crossover study was conducted in healthy Chinese subjects. Test lidocaine patches (T, continuous application for 12h with 3 dosage units) or reference lidocaine patches (R) were randomly given to subjects with an administration sequence of T-R, or R-T, while each single administration was followed by a 3-day washout period. The plasma concertation and corresponding PK parameters of lidocaine were calculated using the non-compartment model of Phoenix WinNonlin8.2. Bioequivalence, adhesion score and safety were analyzed by SAS9.4. Results: A total of 30 subjects were randomized and 29 subjects completed with the samples collected. The 90% CI and the GM ratio for C max , AUC 0-t and AUC 0-∞ , respectively, were 108.07% (101.29%, 115.29%), 105.27% (99.85%, 110.98%), and 105.16% (99.77%, 110.83%) within the range of 80-125%. Adhesion scores were 0 under all period evaluated as noninferiority, and skin irritation was showing no difference between T and R. The incidence of AEs and drug-related AEs were similar between T and R ( p ＞0.05) and no serious AE occurred during the study. Conclusions: T and R were bioequivalent, well tolerated, and no difference in adhesion and skin irritation.