Evaluation of Cefixime-Loaded Chitosan Microspheres: Analysis of Dissolution Data Using DDSolver

The objectives of this study were to fabricate cefixime-loaded chitosan microspheres with the ultimate goal of prolonging drug release and to analyze the influence of various process variables on the properties of microspheres such as mode of drug release. The cefixime-loaded chitosan microspheres were fabricated using a coacervation technique. Various process variables like volume of solvent for chitosan (glacial acetic acid), chitosan concentration, volume of phase separation agent (NaOH solution), and glutaraldehyde concentration were varied to fabricate nine different formulations. Dissolution data were evaluated using DDSolver, new software developed for the kinetic analysis of dissolution data. The microspheres were spherical, porous, and dark brown. They ranged in size from 253.13 +/- 8.4 to 369.1 +/- 13.7 mu m, and the incorporation efficiency varied from 29.9 +/- 32% to 49.3 +/- 4.5%. The F5 formulation with a drug/polymer ratio of 1:3 (w/w) was the most suitable in terms of incorporation efficiency (49.3 +/- 4.5%), flow characteristics (Hausner ratio = 1.4), and drug release properties. The drug release was sustained up to many hours. Fickian diffusion was the primary mode of drug release from all cefixime-loaded chitosan microsphere formulations. These results show that cefixime can be successfully microencapsulated into chitosan shells by coacervation, which is influenced significantly by formulation variables such as chitosan and glutaraldehyde concentration.