Ca-alginate microspheres encapsulated in chitosan beads.

Area of Science:

• Materials Science
• Pharmaceutical Technology
• Biomedical Engineering

Background:

• Oral drug delivery systems aim for controlled and sustained release to improve therapeutic efficacy.
• Chitosan and alginate are biocompatible polymers frequently used in drug delivery applications.
• Developing multi-layered systems can enhance drug encapsulation and release profiles.

Purpose of the Study:

• To develop and characterize novel chitosan beads incorporating Ca-alginate microspheres for oral sustained drug delivery.
• To investigate the drug release characteristics of the developed system using both cationic and anionic model drugs.
• To evaluate the superiority of the multi-layered system over simpler formulations.

Main Methods:

• Ca-alginate microspheres (CAMs) loaded with drug were prepared using membrane emulsification.
• CAMs were encapsulated within chitosan beads (CBs) via ionotropic gelation and polyelectrolyte complexation.
• Ionic cross-linking with tripolyphosphate (TPP) was employed to optimize bead characteristics.
• Drug release studies were conducted using lidocaine.HCl (cationic) and sodium salicylate (anionic) as model drugs.

Main Results:

• Stable and monodisperse drug-loaded CAMs were successfully prepared.
• The encapsulation of CAMs within CBs resulted in a unique three-layer structure.
• The multi-layered system demonstrated superior sustained release compared to simple CBs or CAMs beads.
• Drug release kinetics were influenced by the degree of swelling and the specific drug properties.

Conclusions:

• The developed chitosan beads incorporating Ca-alginate microspheres represent an effective oral sustained drug delivery system.
• The three-layer architecture, comprising a Ca-alginate core, chitosan-alginate membrane, and chitosan-TPP outer layer, is key to enhanced sustained release.
• This system holds promise for improving the delivery of various drugs, including both cationic and anionic compounds.