Formulation design of oral lamotrigine suspension for the treatment of epilepsy

Aim: Lamotrigine is a broad-spectrum anticonvulsant drug widely used as mono- or adjunct therapy in adults and children. The aim of this study was to develop a liquid formulation of lamotrigine to fulfil the unmet needs of children and geriatric epileptic patients. Materials and Methods: Suspension formulation was prepared using Carbopol 974P as a suspending agent. It was evaluated for its sedimentation and re-dispersibility, solubility, morphology, particle-size distribution, rheological properties, pH measurement, uniformity of dosage unit, in vitro drug release behaviour and results were compared with marketed formulation Lamictal tablets. Results: The release profile of marketed product Lamictal tablets and developed lamotrigine oral suspension shows a complete release profile throughout physiological pH in all three media (0.1N hydrochloric acid, 4.5 pH acetate buffer and 6.8 pH phosphate buffer) and shows similar release as a marketed product. Microscopic observation clearly indicates the stability of the suspension (no aggregation of suspended particles) during the storage period of 12 months. The content uniformity of suspension was found well within the specified limits. Conclusion: Lamotrigine oral suspension was developed successfully and found a suitable alternative for a commercially available tablet for the treatment of epilepsy in children and geriatric patients.