Formulation, Optimization, Characterization and In-vitro Evaluation of Sustained Release Floating Microspheres of Carbamazepine

The present study was carried out to formulate and evaluate sustained release floating microspheres of Carbamazepine using ethyl cellulose as the retardant material with high entrapment efficiency and extended release. A 2 factorial design was employed in formulating the GFDDS with Polymer-to-Drug ratio (X1), Acetone-toDichloromethane ratio (X2), and Stirring Speed (X3) as Independent Variables. Four dependent variables were considered: T50%, T80%, % Drug Entrapment Efficiency and Particle size. The main effect and interaction terms were quantitatively evaluated using a mathematical model. Microspheres were prepared by Oil-in-Water (O/W) Emulsion Solvent Evaporation method. A Mixed Solvent System (MSS) consisting of Acetone and Dichloromethane in a 2:1 ratio and water was chosen as aqueous phases, respectively. The prepared microspheres were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and drug loading. The In-Vitro release studies were performed using pH 1.2 SGF. The drug loaded microspheres showed 62-74% of entrapment and release was extended up to 10–12 h. SEM studies showed that the microspheres are spherical and porous in nature. The Infrared spectra and DSC thermograms showed stable character of Carbamazepine in the drug loaded microspheres and revealed the absence of drug-polymer interactions. The data obtained from In-vitro release were fitted to various kinetic models and had high degree of correlation was found in the Korsmeyer and Peppas model. The predicted values agreed well with the experimental values, and the results demonstrated the feasibility of the model in the development of GFDDS. LALJI H. BALDANIYA Department of Pharmaceutics, N. R. Vekaria Institute of Pharmacy, Junagadh,