Formulation, Physical Characterization and in Vitro Release Studies of Aceclofenac Alginate Beads Prepared by Ionotropic Gelation for Sustained Release

The objective of the present study was to microencapsulate the antiinflammatory drug (aceclofenac) to provide sustained release and minimizing or eliminating drug release in the upper gastro intestinal tract. Alginate beads of aceclofenac were formulated by ionotropic gelation and the variables studied includes the effect of concentration of sodium alginate, concentration of cross linking agent (CaCl2), different curing time intervals, different cross linking agents, and addition of chitosan with CaCl2 were evaluated with respect to particle size, surface characteristics, entrapment efficiency and in vitro release behaviors. Infra Red spectroscopic study confirmed the absence of any drug interaction. Differential Scanning Calorimeter (DSC) analysis revealed that the drug was uniformly dispersed in the alginate beads. The mean particle size increases with increasing the polymer concentration and addition of chitosan. The shape of the alginate beads have acceptable sphericity and surfaces were rough which were confirmed by Scanning Electron Microscope photographs. The X-ray diffraction data supports the DSC studies which indicated the decreased crystallinity of drug in the prepared alginate beads. The entrapment efficiency in different formulation varied from 62.18% to 87.96%. The in vitro release profiles were also altered significantly by changing various parameters. The kinetic modeling of the release data indicates that aceclofenac released from the alginate release from the alginate beads followed by the Matrix Higuchi model. From the study it can be concluded that aceclofenac could be successfully prepared by ionotropic gelation technique with high entrapment efficiency and prolonged release characteristics