Development and validation of a new high-performance liquid chromatographic assay of centpropazine, a new antidepressant compound, in serum

Centpropazine is a new anti-depressant compound developed by Central Drug R esearch Institute, Lucknow (India). We report here the development and vali dation 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 C-18 c olumn 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 enh ance 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 m u g ml(-1), 0.04-2.5 mu g ml(-1) and 2.5-80 ng ml(-1) respectively were dev eloped. The lowest limit of quantitation of the method was 2.5 ng ml(-1) re quiring 4 ml serum, 40 ng ml(-1) requiring 0.5 ml serum and 312 ng ml(-1) r equiring 50 mu l serum sample. All these methods were fully validated in hu man serum and extended to monkey and rat serum, The recovery of centpropazi ne at 5, 80, 625, 1280 and 2500 ng ml(-1) ranged between 92 and 105%. The w ithin 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. Overal l 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) iv do se. The chromatograms of treated rat serum exhibited three well resolved pe aks of metabolites and one of them was identified as hydroxy-metabolite of centpropazine. (C) 1999 Elsevier Science B.V. All rights reserved.