Chitosan-alginate complex for the controlled delivery of α-lipoic acid in diabetes therapy: Modulation by montmorillonite and glutaraldehyde

Abstract

Development of safe, therapeutically effective, and patient-compliant drug delivery systems remains a key focus in pharmaceutical research, particularly for controlled-release formulations. In this study, Lipoic acid-loaded chitosan-alginate polyelectrolyte complexes have been successfully prepared, incorporating varying concentrations of Montmorillonite (MMT) nano clay as a filler and glutaraldehyde (GA) as a crosslinking agent. The effects of varying GA and MMT concentrations on drug loading and encapsulation efficiency are investigated in detail. The structural characteristics of the complexes are analysed using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The in vitro drug release is studied over 50 h using a UV-visible spectrophotometer at two pH levels (1.2 and 7.4), demonstrating that the cumulative release of Lipoic acid is pH-dependent. Additionally, cumulative drug release decreases with increasing concentrations of GA and MMT, likely due to increased crosslinking density and restricted swelling of the complex. Glucose uptake assays show significant improvement across all formulations, and MTT assays confirmed that the drug formulations are non-toxic, maintaining cell viability. Overall, these results suggest that the lipoic acid-loaded chitosan-alginate polyelectrolyte complexes are promising candidates for future development in treating insulin resistance and type 2 diabetes, with the potential to enhance therapeutic efficacy through controlled drug release.