Micellar buccal film for safe and effective control of seizures: Preparation, in vitro characterization, ex vivo permeation studies and in vivo assessment

Abstract

The current research article focused on formulating an easily applied, water-based buccal film loaded with the antiepileptic drug, lamotrigine (LTG). The designed film can be comfortably administered by epileptic patients to ensure a controllable therapeutic efficacy against seizures. The solubility of LTG in water was significantly improved by micellar solubilization. Upon testing several surfactants, three of them (Synperonic PE/P84, Brij L23, and Brij 78) achieved maximum possible solubility for LTG and were characterized for their micellar size, cloud point, and % transmittance. Selected micellar systems were incorporated within a buccal film prepared using solvent casting method based on either gelatin or polyvinylpyrrolidone (3%w/v) with 1.5%w/v propylene glycol as a plasticizer. Different micellar films were characterized for their physicochemical characteristics, swelling index, folding endurance, drug content uniformity, and in vitro LTG release. From the tested formulations, one formulation; LTG-BF1 (in which Brij 78 was used for the micellar solubilization and gelatin as the matrix former), was selected as the optimum and extensively studied for mucoadhesion, ex vivo permeation studies by Franz diffusion cells and confocal laser scanning microscopy. Results showed superior enhanced permeation of micellar film. LTG-BF1 was evaluated for the in vivo performance using rats. Status epilepticus was induced in rats by injecting Pentylenetetrazol (PTZ) i.p. at an initial dose of 30 mg/kg, followed by 10 mg/kg every10 min till 60 min. A group of rats receiving the designed buccal formulation (20 mg/kg) was compared with a group receiving the same dose of the oral market product and the normal control and PTZ groups. Rats receiving LTG-BF1 recorded reduced seizure scores at all stages, longer latency time, and higher threshold PTZ dose compared to PTZ and market product groups. In addition, LTG-BF1 reduced brain concentrations of TNF-α and TGF-β with an elevation of EAAT2 and GABA brain contents compared to PTZ and market product groups and ameliorated neuronal damage. In conclusion, LTG-loaded buccal micellar film proved a superior antiepileptic effect in PTZ induced acute epileptic model.