Pharmacokinetic comparison of two formulations of talniflumate 370 mg tablets in healthy Korean volunteers

Background: Talniflumate, a prodrug of nifiumic acid, is a potent analgesic and anti-inflammatory drug that has been widely used for the treatment of rheumatoid diseases. Objective: The aim of this study was to compare the pharmacokinetics and to evaluate the bioequivalence of two formulations of talniflumate 370 mg tablets (test formulation: Flumagen (R) 370 mg tablet; reference formulation: Somalgen (R) 370 mg tablet). Methods: A randomized, open-label, single dose, two-sequence, two-period crossover clinical study was conducted. After oral administration of the study drug in each period, blood samples were collected up to 15 hours post-dose. The plasma concentration of nifiumic acid, a metabolite of talniflumate, was determined using HPLC-MS/MS. The pharmacokinetic parameters were estimated by non-compartmental method. Results: The maximum plasma concentration (C-max) and area under the concentration-time curve from zero to the time point with the last measurable concentration (AUC(last)) for the test formulation were 290.7 +/- 199 mu g/L and 1,154 +/- 643 mu gxh/L, respectively, and the corresponding values for the reference formulation were 286.8 +/- 193 mu g/L and 1,151 +/- 577 mu gxh/L, respectively. The geometric mean ratio and 90% confidence intervals (CI) of the test formulation to the reference formulation for the C-max and AUC(last) were 0.983 (0.829 - 1.166) and 0.979 (0.856 - 1.121), respectively. Conclusions: The pharmacokinetic profiles of the test and reference formulations were found not to be significantly different, meeting the Korean regulatory criteria for bioequivalence.