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Updated: Apr 29, 2026
Author Spotlight: Advancing Therapeutics with Biocompatible Sodium Alginate Hydrogel Microspheres
Published on: June 7, 2024
Development and evaluation of pH-sensitive sodium alginate/chitosan microparticles containing the antituberculosis
Loreana Lacerda1, Alexandre Luis Parize2, Valfredo Fávere1
1Laboratório Quitech, Departamento de Química, Universidade Federal de Santa Catarina, Brazil.
Abstract:
This paper describes the encapsulation of a high molecular weight molecule rifampicin (RIF) in sodium alginate/chitosan microparticles, which provided controlled-release when evaluated in vitro. The microparticles were prepared by the coacervation technique. To evaluate and select the best encapsulation method two approaches were applied: coacervation (MCP method 1) and impregnation (MCP method 2). The microparticles obtained were analyzed by DSC, DRIFT, XRD and SEM and also the loading efficiency, swelling degree (SD) and in vitro release were determined. The results obtained showed that the alginate/chitosan microparticles represent an efficient system for the controlled-release of RIF. At acidic pH, the release of 20% of the drug occurred in 2h, and at pH6.8 a rapid increase in the release rate was observed up to 100%. The mechanism involved in the release was Super Case II kinetics since n>1 (n=1.09 and 1.13 for microparticles produced by methods 1 and 2, respectively), indicating that the release was related to diffusion, swelling, relaxation and erosion processes. The dissolution efficiencies were similar for both formulations, and the f2 values of ≥50 indicated the similarity between the two profiles, under the assumption of a maximum allowable difference of 10%.
Insights
Sodium alginate/chitosan microparticles effectively encapsulate rifampicin (RIF) for controlled drug release. These microparticles demonstrate efficient RIF delivery, with release kinetics influenced by pH and polymer matrix interactions.
Area of Science:
- Materials Science
- Pharmaceutical Sciences
- Biotechnology
Background:
- Controlled drug delivery systems are crucial for improving therapeutic efficacy and patient compliance.
- Rifampicin (RIF), a key antibiotic, requires effective delivery mechanisms to combat bacterial infections.
- Alginate and chitosan are biocompatible polymers with potential for microparticle-based drug encapsulation.
Purpose of the Study:
- To develop and evaluate sodium alginate/chitosan microparticles for the controlled release of rifampicin (RIF).
- To compare two encapsulation methods: coacervation and impregnation, for optimizing RIF loading and release.
- To characterize the microparticles and elucidate the drug release mechanism.
Main Methods:
- Microparticles were prepared using coacervation and impregnation techniques.
- Characterization involved Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM).
- In vitro drug release studies were conducted at different pH values, along with swelling degree (SD) and loading efficiency assessments.
Main Results:
- Alginate/chitosan microparticles demonstrated efficient encapsulation and controlled release of RIF.
- Drug release was pH-dependent, with rapid release observed at pH 6.8.
- Release kinetics followed Super Case II transport (n>1), indicating a combination of diffusion, swelling, relaxation, and erosion.
Conclusions:
- Sodium alginate/chitosan microparticles are a promising system for controlled rifampicin delivery.
- The coacervation and impregnation methods yielded similar dissolution profiles, suggesting robustness in formulation.
- The Super Case II release mechanism highlights the potential for sustained and predictable drug release.
