Formulation and Evaluation of New Sustained Release Floating Microspheres of Cilnidipine by Solvent-Diffusion Evaporation Technique

The purpose of the present investigation was to develop a gastro-retentive cilnidipine loaded floating microspheres. The floating microspheres of cilnidipine were prepared by the solvent evaporation method for oral drug delivery using HPMCK4M and ethyl cellulose as polymers. The drug loaded microspheres were evaluated for particle size, drug content, entrapment efficiency and floating time. The in-vitro study was performed in pH 1.2 to determine the amount of drug released. Field emission scanning electron microscopy (SEM) was performed to check the surface morphology of microspheres. The mean particle size of the microspheres was in the range of 226.85 – 339.42µm. The drug content of the floating microspheres was more than 70% and drug entrapment efficiency of microspheres obtained between 64.64 – 83.0%. The in-vitro buoyancy was more than70%. Cumulative % of drug release obtained between 73.12 – 89.68%. Field emission scanning microscopy results showed that the prepared microspheres were smooth and spherical.The study reveals that more the particle size extended the floating time, this methods reveals that the drug content of the microspheres enhanced as the amount of polymer increased or increased in ethyl cellulose concentration also leads to increase in entrapment efficiency and particle size. Cumulative % drug release decreased as ethyl cellulose concentration increased. Keywords: cilnidipine, microspheres, floating drug delivery system, entrapment efficiency, cumulative drug release, ethyl cellulose, Field emission scanning electron microscopy, polymer, concentration