5-ASA loaded chitosan-Ca-alginate microparticles: Preparation and physicochemical characterization.

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Biomedical Engineering

Background:

• Effective colon drug delivery is crucial for treating inflammatory bowel diseases.
• Developing stable microparticle systems for targeted drug release remains a challenge.

Purpose of the Study:

• To prepare and characterize chitosan-calcium-alginate microparticles for colon-specific delivery of 5-aminosalicylic acid (5-ASA).
• To evaluate the stability and morphology of the microparticles and ensure no degradation of 5-ASA during preparation.

Main Methods:

• Spray-drying of 5-ASA/sodium alginate solution to form microparticles.
• Cross-linking and coating with calcium chloride (CaCl2) and chitosan.
• Characterization using Scanning Electron Microscopy (SEM), Confocal Laser Scanning Microscopy (CLSM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and X-ray diffraction (XRD).

Main Results:

• Spherical microparticles with a mean diameter <10µm were obtained, though some flattened shapes were observed.
• CLSM confirmed chitosan localization in the particle wall and homogeneous alginate distribution, resulting in a negative particle charge.
• FTIR, DSC, and XRD analyses indicated no covalent interaction between 5-ASA and the polymers, with 5-ASA being molecularly dispersed.

Conclusions:

• Chitosan-calcium-alginate microparticles are suitable for encapsulating 5-ASA without degradation.
• The developed microparticles demonstrate potential for targeted colon drug delivery systems.