Abstract

SIMULTANEOUS ESTIMATION OF CARBODENAFIL AND DESMETHYL CARBODENAFIL FROM HUMAN PLASMA BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY

Dr. Macharla Venkata Ramana, Dr. T. Shyam, K. N. Rajinikanth, Dr. V. Kiran Kumar, Dr. VVSS. Appala Raju and *Dr. N. Appala Raju

Abstract

A simple, sensitive and fast throughput liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for the simultaneous estimation of Carbodenafil and its metabolite Des-methyl Carbodenafil in human plasma, using respective deuteriated drug as internal standards. The method involved Liquid-Liquid Extraction of the analytes and internal standards from human plasma. The chromatographic separation was achieved on a ACE, CN, (150×4.6mm and 5μm particle size) analytical column using isocratic mobile phase, consisting of 5mM Ammonium Format and Acetonitrile (25:75 v/v), at a flow-rate of 1.0 mL/min with 90% flow splitting. The parent→product ion transitions 475.40→/283.20, 461.30→ /283.20, 478.40→/283.20, 469.30→/283.20 (m/z) for Carbodenafil, Des-methyl Carbodenafil, Carbodenafil-D3 and Des-methylCarbodenafil-D8 respectively were monitored on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring (MRM) positive ion mode. The method was validated over the concentration range of 2.00-1000 for Carbodenafil and Des-methyl Carbodenafil. The mean recovery values for both the drugs from spiked plasma samples were reproducible. The method was rugged and rapid with a total run time of 4.0 minutes.

Keywords: Carbodenafil; Des-methyl Carbodenafil; LC–MS/MS; Liquid/liquid extraction.