A Sensitive RP-HPLC Method for Simultaneous Estimation of Diethylcarbamazine and Levocetirizine in Tablet Formulation.

A simple, sensitive and reproducible method was developed and validated for the simultaneous estimation of diethylcarbamazine and levocetirizine in its tablet formulation by reverse phase high performance liquid chromatography using Waters1515 HPLC with UV detector at the λ(max) of 224 nm, using Princeton Sphere-100 C(18) (250×4.6 mm. 5 μ) column. The mobile phase used was 20mM potassium dihydrogen orthophosphate buffer (pH: 3.2):acetonitrile (50:50 v/v) with isocratic flow (flow rate 1 ml/min) and the pH was adjusted with orthophosphoric acid. Losartan potassium was used as an internal standard. The compounds diethylcarbamazine, levocetirizine and losartan potassium were eluted at 2.12, 4.27 and 5.96 min, respectively. The peaks were eluted with better resolution. The method was accurate with assay values of 96.32 and 93.04% w/w, precise (%RSD) with intra-day 1.72 and 1.89 and inter-day 1.85 and 1.92, recoveries 102.86 and 101.1% w/w, which are very sensitive with limit of detections (LOD)'s 75, 50 ng/ml and limit of quantification (LOQ)'s 100, 75 ng/ml and linear with R(2) values 0.994 in the range of 5 to 30 μg/ml 0.1 to 1 μg/ml for diethylcarbamazine and levocetirizine, respectively. Hence this method can be applied for quantification of different formulations containing diethylcarbamazine and levocetirizine simultaneously.