Pharmacokinetic blood samples will be collected over 168 hours post dose. Venous blood (2 ml each) is taken immediately before dosing (pre-dose) and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, 24, 36, 48, 72, 96, 120, 144 and 168 hours post dose to determine the lamotrigine concentration in serum. Drug concentration in serum at different time points will be determined for each subject with a validated bioanalytical method using LC/MS/MS method. The main pharmacokinetic parameters such as Cmax, tmax, AUC(0-inf), AUC(0-t), t1/2, λz, CL/F and Vd/F are calculated for subjects using non-compartment analysis method.