Optimization of Thermo-reversible Nasal Gel of Carbamazepine for Better Control in Chronic Epilepsy

The aim of present work was to formulate thermosensitive in situ gel of carbamazepine (CBZ), an anti-epileptic agent. In situ nasal gel of CBZ was formulated by cold method using Pluronic F68 and Pluronic F127 as thermoreversible stimuli sensitive polymer along with two different grades of hydroxypropyl methyl cellulose as mucoadhesive polymer. It is thought that the thermo-reversion and mucoadhesion would synergistically enhance the residence time of the drug in the nasal cavity and also impart better penetration of the drug to brain for the site-specific activity. The sustained release obtained from the viscous gel makes the treatment even better especially in the chronic epileptic conditions like tonic–clonic seizures. The prepared formulations were evaluated for pH, clarity, in vitro gelation, gelling strength, mucoadhesion, in vitro drug release and accelerated stability studies. Results have shown that final batches of in situ gels were having desired gelation temperature to provide pourable ‘Sol’ form at room temperature and ‘Gel’ form in the nasal cavity with a good gel strength and mucoadhesion required for nasal retention. Formulations showed polymer concentration dependent drug release retardation over a period of 6 h.