Cross-linked Chitosan Microspheres: Preparation and Evaluation as a Matrix for the Controlled Release of Pharmaceuticals

Abstract

Chitosan microspheres having good spherical geometry and a smooth surface were prepared by the glutaraldehyde cross-linking of an aqueous acetic acid dispersion of chitosan in paraffin oil using dioctyl sulphosuccinate as the stabilizing agent. Microspheres having different degrees of swelling were made by varying the cross-linking density. Microspheres were prepared by incorporating theophylline, aspirin or griseofulvin. Drug incorporation efficiencies exceeding 80% could be achieved for these drugs. In-vitro release studies of these drugs were carried out in simulated gastric and intestinal fluids at 37 degrees C. It was observed that the drug release rates were influenced by the cross-linking density, particle size and initial drug loading in the microspheres.

Biomedical Activity of Chitin/Chitosan Based Materials—Influence of Physicochemical Properties Apart from Molecular Weight and Degree of N-Acetylation

“…For example, the drug release rates of theophylline, aspirin and griseofulvin from chitosan microspheres prepared by the emulsion cross-linking of a chitosan solution in paraffin oil as an external medium were influenced by cross-link density, particle size and initial drug loading [116].…”

Formulation and Characterization of Glutaraldehyde Cross-Linked Chitosan Biodegradable Microspheres Loaded with Famotidine

“…This problem can be countered by irreversible chemical crosslinking. It has been demonstrated that drug diffusion from chitosan microspheres can be controlled by crosslinking with a dialdehyde such as glutaraldehyde [7].…”

Mucoadhesive Microspheres Based Formulation Development of Ziprasidone Hydrochloride for Nasal Delivery

“…Determination of melting point of Ziprasidone Hydrochloride Melting point of pure Ziprasidone Hydrochloride was found to be 307 0 C [17] . Identification by thermal analysis (DSC) Melting point of Ziprasidone Hydrochloride was confirmed with its individual DSC thermogram and was found satisfactory [16,18] .…”

“…Absorbance of all solutions was measured at 284 nm against distilled water as a blank. The calibration curve was prepared by plotting absorbance versus concentration of drug [16,17] .…”