Determination of centpropazine and its metabolite in rat serum by high-performance liquid chromatography and...

A new HPLC assay method was developed for the simultaneous assay for centpropazine (antidepressant) and its hydroxylated metabolite (II) to assess their pharmacokinetics and metabolism characteristics. Rat serum samples were extracted with ether, backwashed with n-hexane and injected onto the HPLC system, which used a C18 column, gradient elution and fluorescence detection at 250 Ex/350 nm Em. Variations in intra- and inter-batch accuracy and precision were within acceptable limits of < +/- 20% at low and < +/- 15% at higher concentrations. Samples were stable in autosampler prior to injection and after multiple freeze-thaw cycles. Linearity was observed between 0.625 and 20 ng/ml for both I and II in serum. Overall the method developed was highly sensitive and could be employed for a wide range of studies.