A rapid and sensitive HPLC method for the analysis of celecoxib in human plasma: application to pharmacokinetic studies

Background and the purpose of the study: A suitable high-performance liquid chromatography (HPLC) method for determination of celecoxib levels in plasma is of prime need for the pharmacokinetics and bioequivalence studies of celecoxib preparations. The present study describes a simple, rapid, sensitive, reliable, and economic HPLC method for determination of celecoxib in human plasma which is more feasible than reported celecoxib HPLC assays. The drug and internal standard were extracted using n-hexane /isoamyl alcohol (97:3) and analyzed on a C18 µ-Bondapak HPLC column with KH2PO4 (0.01M, pH= 4) - acetonitrile (60:40) as the mobile phase, at 260 nm. The method involved simple one-step liquid-liquid extraction procedure with extraction recovery of greater than 90%. The standard curve covering 0.01-2.0 μg/ml concentration range was linear. The coefficients of variation and relative errors for inter- and intra-day assay ranged from 5.67 to 9.83 and 0.35 to 7.89 %, respectively. HPLC assay was performed isocratically on a reversed-phase column with UV detection. By this method a limit of quantification of 10 ng/ml of a sample size of 0.5 ml is achieved which is comparable or even better than the reported methods. The developed method was applied to the analysis of celecoxib levels in plasma collected from healthy volunteers who participated in a pharmacokinetic study.