Original Articles: 2013 Vol: 5 Issue: 10
Formulation of immediate release lamotrigine tablets and bioequivalence study
Abstract
Lamotrigine tablets were compressed directly by means of Avicel PH102, sodium starch glycolate, magnesium stearate, Aerosil 200 and PVPK25. A rapid, sensitive and simple high-performance liquid chromatographic (HPLC) method for the determination of lamotrigine in plasma is described. The drug was extracted from one mL of each rabbits plasma sample was transferred into a 15 mL tube fitted with a polyethylene cap 1 mL acetonitrile were added to the sample. The supernatant was injected into the HPLC system. The drug and the internal standard (carbamazepine) were eluted from C18 Zorbax ODS(4.6 x 250mm, USA) column at ambient temperature with a mobile phase consisting of acetonitrile and 20mM potassium dihydrogen phosphate buffer (35:65,v/v) and adjusted to (pH7) using 1NNaOH, at a flow rate of 1.5 ml min-1 and the detector was monitored at 210 nm. Quantitation was achieved by measurement of the peak-area ratio of the drug to the internal standard and the lower limit of detection for lamotrigine in plasma was 0.491 μg ml-1. The intraday precision ranged from 0.801-7.692 % coefficient of variation (CV) and accuracy ranged from 0.048-4.9(relative error%) for samples. The relative recoveries of lamotrigine ranged from from 95.10 to 101.89%. The method was applied in studying the pharmacokinetics of lamotrigine administered orally to rabbits. This reliable micro-method would have application in pharmacokinetic studies of lamotrigine. The relative percentage bioavailability of prepared lamotrigine tablets with respect to the commercially available Lamictal® tablets was 134.68%.