Pharmacokinetic equivalence study of nonsteroidal anti-inflammatory drug etoricoxib

The current study aimed to evaluate whether a generic product of etoricoxib 120 mg film-coated tablet (the test drug) was bioequivalent to the reference product (Arcoxia® film-coated tablet 120 mg).

This was a randomized, open-label, two-sequence, crossover study under fasting condition, with a 14-day washout period, involving 26 healthy adult male and female subjects. Blood samples were taken and analyzed for plasma concentrations of etoricoxib (Chemical Abstracts Service [CAS] 202409-33-4) using a high-pressure liquid chromatography-ultraviolet detector (HPLC-UV) system capable of measuring etoricoxib concentrations ranging from 5.00 to 5002.90 ng/mL, with the lowest limit of quantitation of 5.00 ng/mL. A noncompartmental method was used to determine the pharmacokinetic parameters of a single-dose administration of the drug, including the area under plasma concentration-time curve from time zero to the time of last observed concentration (AUC_0- ), the area under plasma concentration-time curve from time zero to infinity (AUC_0-∞), the maximum plasma concentration (C_max), the time to reach the maximum plasma concentration (t_max), and the terminal half-life (t_½).

After a single-dose administration of etoricoxib 120 mg film-coated tablet, the mean (SD) values for the AUC_0-72h and C_max of the test drug were 45913.42 (13142.19) ng·h/mL and 3155.93 (752.81) ng/mL, respectively; the values for the reference drug were 44577.20 (13541.85) ng·h/mL and 2915.13 (772.81) ng/mL, respectively. The geometric mean ratios (90% CIs) of the test drug/reference drug were 103.40% (98.70%-108.32%) for AUC_0-72h and 109.26% (100.18%-119.18%) for C_max. No clinically significant differences in t_max and t_½values were found between the test drug and the reference drug. No adverse events were experienced by the subjects during this study.

The present study demonstrated that the evaluated generic etoricoxib 120 mg film-coated tablets were bioequivalent to the reference drug.