Moulded cross-linked chitosan matrix systems for controlled drug release

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Biomaterials Engineering

Background:

• Chitosan is a versatile biopolymer with potential in drug delivery.
• Developing controlled-release matrix systems is crucial for improving therapeutic efficacy.
• Understanding drug release mechanisms from chitosan matrices is essential for formulation design.

Purpose of the Study:

• To prepare and characterize matrix-type drug delivery systems using cross-linked chitosan.
• To evaluate the in vitro drug release profiles and their dependence on pH.
• To investigate the influence of different cross-linking agents on system properties and drug release kinetics.

Main Methods:

• Preparation of cross-linked chitosan gels in a matrix format.
• Evaluation of physical properties, drug content, surface morphology, and swelling.
• In vitro drug release studies at pH 5.8 and pH 7.4.
• Kinetic modeling of drug release profiles using the release exponent (n).

Main Results:

• Moulded chitosan matrix systems exhibited significantly slower drug release than immediate-release tablets.
• Chitosan cross-linked with tripolyphosphate showed pH-dependent release: anomalous transport (n=0.75) at pH 5.8 and Fickian diffusion (n=0.40) at pH 7.4.
• Chitosan cross-linked with sodium lauryl sulphate displayed higher swelling and predominantly Fickian diffusion (n≈0.25-0.41).

Conclusions:

• Cross-linked chitosan matrices offer a viable approach for developing controlled drug delivery systems.
• The choice of cross-linking agent significantly impacts drug release mechanisms and pH-dependency.
• These findings provide valuable insights for designing tailored chitosan-based drug delivery formulations.