Determination of Entacapone in Pharmaceutical Preparations by Liquid Chromatography

A reverse phase high performance liquid chromatographic method (HPLC) has been developed for the estimation of entacapone in its dosage forms using C18 column. The mobile phase (acetonitrile and 20mM potassium dihydrogen phosphate, P^H 3.5) was pumped at a flow rate of 1 ml/min in the ratio of 80:20 and the eluents were monitored at 320 nm. The intra-and inter-day variation was found to be less than 2% showing high precision of the assay method. The mean recovery of the drug from the solution containing 200 or 300 μg/ml was 99.66 ± 1.20% indicating high accuracy. The proposed HPLC method may be used for determining entacapone in bulk drug samples or in pharmaceutical dosage forms