Development and validation of a new high-performance liquid chromatographic assay of centpropazine, a new...

Centpropazine is a new anti-depressant compound developed by Central Drug Research Institute, Lucknow (India). We report here the development and validation of a new HPLC assay of a parent drug in the serum of humans, monkeys and rats for pharmacokinetic studies. Centpropazine was eluted on a C18 column with a mobile phase consisting acetonitrile phosphate buffer (60:40) pumped at 1.5 ml min(-1) flow rate and quantitated by UV detector at 270 nm. Considering the sample volume available from different species and to enhance the sensitivity of assay, three sample clean up methods requiring 0.05, 0.5 and 4 ml serum for a linear quantitation range of 312.5 ng ml(-1)-5 microg ml(-1), 0.04-2.5 microg ml(-1) and 2.5-80 ng ml(-1) respectively were developed. The lowest limit of quantitation of the method was 2.5 ng ml(-1) requiring 4 ml serum, 40 ng ml(-1) requiring 0.5 ml serum and 312 ng ml(-1) requiring 50 microl serum sample. All these methods were fully validated in human serum and extended to monkey and rat serum. The recovery of centpropazine at 5, 80, 625, 1280 and 2500 ng ml(-1) ranged between 92 and 105%. The within and between run variability in precision and accuracy were less than 10% and the drug in serum was stable up to three freeze-thaw cycles. Overall the method is simple, quick and robust for biopharmaceutical applications. The method was applied to analyse concentrations of centpropazine in rat serum after administering single 20 mg kg(-1) peroral and 5 mg kg(-1) i.v. dose. The chromatograms of treated rat serum exhibited three well resolved peaks of metabolites and one of them was identified as hydroxy-metabolite of centpropazine.