Comparative fasting bioavailability of two clopidogrel formulations in healthy Mediterranean volunteers: an in vitro–in vivo correlation

OBJECTIVE: The aim of this study was to evaluate the bioequivalence of two drug products, generic clopidogrel bisulfate 75 mg film-coated tablets versus the reference Plavix(®) clopidogrel bisulfate 75 mg film-coated tablets. METHODS: Bioequivalence of tablets was tested by comparisons against the reference brand product in accordance with the requirements of the Declaration of Helsinki, the current Good Clinical Practice Guidelines, and the International Conference on Harmonization. RESULTS: The relationship between concentration and peak area ratio was found to be linear within the range 24.500–1,836.600 pg/mL for clopidogrel. The correlation coefficient (r) was always greater than 0.99 during the course of the validation. Statistical comparison of the main pharmacokinetic parameters showed no significant difference between test and reference. The point estimates (ratios of geometric mean) were 104.122%, 104.184%, and 109.091% for areas under the plasma concentration–time curve (AUC) AUC(0-last), AUC(0-∞), and peak plasma concentration C(max), respectively. These pharmacokinetic parameter values of clopidogrel and its main metabolite lie within the bioequivalence limit (80%–125%) specified by the US Food and Drug Administration and the European Medicines Agency. CONCLUSION: The tested drug product was bioequivalent to the reference drug under fasting conditions and had the same safety profile, which is important to achieve equivalent therapeutic effect with the reference.