Simultaneous estimation of raloxifene and cladrin by HPLC: application to metabolic stability studies in different species.

A reliable, sensitive, HPLC method was developed and validated to simultaneously quantify raloxifene (RLX) and cladrin (CLD). The C18 column was used to analyze RLX and CLD at λ 285 and 249 nm. The mobile phase was composed of acetonitrile and 35:65% v/v aqueous solution of 0.1% formic acid. The method was linear over the linearity range of 0.078-20 μg/ml, and the limit of detection and limit of quantification for RLX and CLD were 0.191 and 0.228 and 0.581 and 0.69 μg/ml, respectively. In accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines, the developed method is precise and accurate for simultaneous estimation of RLX and CLD with applications in liver microsomal stability in mice, rabbits, dogs, monkeys and humans.