Spectrophotometric determination of clopidogrel bisulfate

Two simple and high sensitive spectrophotometric methods have been developed for the quantitative determination of clopidogrel bisulfate (CLPB), in pure form and in pharmaceutical formulations, through H-point standard addition method (HPSAM) which showed suitable abilities to resolve accurately overlapped absorption spectra of the compounds by simultaneous determination of CLPB in its binary mixture with aspirin (ASP), and the other method is ion-pair formation reactions with some sulphonphthalein, e.g. bromophenol blue (BPB), bromocresol purple (BCP), bromocresol green (BCG), and bromoxylenol blue (BXB). The reaction conditions were studied and optimized. The proposed methods are rapid, accurate, sensitive, selective and cost effective and the methods were successfully applied to the analysis of commercial tablets as Plavix, Borgavix, and Colsprin (authentic sample). Statistical treatment of the results was performed with regard to accuracy and precision using student's t- and F-tests at 95% confidence level.