Analysis of Aspirin, Prasugrel and Clopidogrel in Counterfeit Pharmaceutical and Herbal Products: Plackett-Burman Screening and Box-Behnken Optimization.

An isocratic reversed-phase high-performance liquid chromatographic method has been developed and validated for the simultaneous determination of aspirin, prasugrel HCl and clopidogrel bisulfate in the presence of clopidogrel-related compound (impurity-A) in focus on counterfeit. This method was used to determine counterfeited antiplatelet drugs in two substandard Indian pharmaceutical products sold on the market in Yemen and two traditional herbal medicines sold on the market in China. Thin layer chromatography and mass spectrometry of counterfeit herbal medicines have additionally been carried out to verify the identification of adulterants. Chromatographic separation was performed on Inertsil ® ODS-3 C18 (4.6 × 250 mm, 5 μm) with isocratic mobile phase elution containing a mixture of acetonitrile: (25 mM) potassium dihydrogen phosphate buffer, pH 2.7 adjusted with 0.1 M o-phosphoric acid (79: 21, v/v), at a flow rate of 1 mL/min and UV detection at 220 nm. Designs of experiment methodology, Plackett-Burman and Box-Behnken designs were used for the screening and optimization of the mobile phase composition. The method validation was also performed in accordance with the International Council on Harmonization (ICH) guidelines. The method developed for routine analysis was found to be sensitive, simple, accurate and highly robust. The results were statistically compared to reference methods using Student's t-test and variance ratio F-test at P < 0.05.