Investigating the correlation between physicochemical properties and pharmacokinetic parameters of some marketed brands of celecoxib

Abstract

Introduction: Celecoxib is a COX-2 selective inhibitor non-steroidal anti-inflammatory drug (NSAID). Celecoxib is available by prescription in capsule form. The US Food and Drug Administration (FDA) has defined bioequivalence (BE) as the absence of a significant difference in the rate and extent of active ingredient between test and refrence products when administered at the same dose under similar conditions in an appropriately designed study.

Aim: Aim of This study was to evaluate the pharmacokinetics (PK) and bioequivalence (BE) of different products of celecoxib capsules. Matherials and mehtod: For in vitro evaluation, content uniformity, assay and dissolution tests were performed. A randomized, single dose, two-period, cross over study in healthy Iranian male fasting volunteers was designed. A 1-week washout period separated the two periods. For analysis of PK parameters blood sampling was performed before and after drug administration in various time points up to 24 h. Celecoxib concentration in plasma was determined using a developed high performance liquid chromatography method. Results: Both formulations passed the assay, content uniformity, and dissolution tests acceptance value. PK parameters, representing the rate and the extent of celecoxib absorption were calculated and analyzed for two formulations. The 90 % C.I.(Confidence interval) obtained by analysis of variance for the ratios of Cmax, AUC0–t, and AUC0–∞ were 63.33–86.69, 57.28–104.79 and 59.81–98.41 % respectively, did not meet the criteria for BE (80–125 %). Conclusion: Administration of a single dose of test and reference formulations did result in statistically significant differences in vivo BE parameters in healthy Iranian male volunteers. Thus in the case of rate and extent of absorption the test and reference formulations were not considered bioequivalent.