Novel expandable gastro retentive system by unfolding mechanism of levetiracetam using simple lattice design - Formulation optimization and in vitro evaluation

The aim of the present study was to develop and characterize a novel expandable gastro-retentive dosage form (GRDF), based on unfolding mechanism. The dosage form consists of a drug loaded the polymeric patch, folded into a hard gelatin capsule. Gastro retention obtained from unfolding and swelling of the patch and its adhesion to the gastric mucosa. Therefore in this work, a gastro retentive patch of levetiracetam was developed using simple lattice design considering concentration of Hydroxy Propyl Methyl Cellulose, Carbopol 934P and Xanthan gum as independent variables. A response surface plot and multiple regression equations were used to evaluate the effect of independent variables on dependent variables such as mucoadhesive strength (g/cm2) and t90 (h). The prepared patches were evaluated for weight and thickness variation, mechanical properties, in vitro drug release and unfolding behavior. The absence of drug-polymer interaction and uniform drug dispersion in the polymeric patches was revealed by FT-IR, DSC, XRD and SEM. The results indicates, the novel GRDF based on unfolding mechanism can be alternative for other mucoadhesive dosage forms which will provide sustained release for 12 h.