A RELIABLE AND COST EFFECTIVE LIQUID CHROMATOGRAPHIC METHOD FOR THE ESTIMATION OF PHENOBARBITAL AND PHENYTOIN IN PHARMACEUTICAL FORMULATIONS

Abstract

A simple, reliable and cost effective RP-HPLC method for the simultaneous determination of Phenobarbital and Phenytoin in pharmaceutical formulations was developed and validated. Chromatographic separation of two drugs was achieved on a Kromasil C18, (250x4.6nm, 5m) column by using the mobile phase consisted of methanol: water in the ratio 75:25 (v/v) at a flow rate of 0.9mL/min and the wavelength of detection was at 238 nm. The retention time for Phenobarbital and Phenytoin were found to be 6.10 and 8.10 min respectively. The linearity of the developed method was tested over a concentration range of 6-42g/mL for Phenobarbital and 10-70g/mL and the correlation coefficient (r2) of regression was 0.998 for phenobarbital and 0.9979 for phenytoin which are almost equal to 1. The limit of quantification was 1.5g/mL for Phenobarbital and 0.7g/mL for Phenytoin and the limit of detection was 0.45g/mL for Phenobarbital and 0.2g/mL for Phenytoin. The mean percentage recoveries were 98.93% for Phenobarbital and 100.16% for Phenytoin respectively.