Sustained drug delivery of the β-blocker acebutolol hydrochloride via chitosan–bilimbi leaf extract films

Abstract

This study presents the development of biocompatible polymeric films designed for the sustained release of the β-blocker acebutolol hydrochloride (AH). The films were fabricated using chitosan (CH), a biodegradable biopolymer, in combination with varying concentrations of Averrhoa bilimbi leaf extract (ABE), a natural additive with potential antimicrobial properties. The composite films were characterized using crystallinity, spectroscopic, mechanical, thermal, and morphological analyses. Functional testing included swelling studies, cumulative drug release profiling, cytotoxicity assessments, and microbial resistance assessments. The results indicated that the incorporation of ABE positively influenced the structural, mechanical, thermal and morphological properties, including swelling behaviour, thickness, and drug release kinetics. The film with the lowest ABE concentration showed optimal swelling (∼200%) and the highest drug release (∼25%), along with notable drug loading (∼78%) and encapsulation efficiency (∼19%). The release kinetics followed the Higuchi and Korsmeyer–Peppas models, indicating a non-Fickian diffusion mechanism. Importantly, the AH integrity was maintained throughout the fabrication process, and all the films exhibited excellent biocompatibility (90% cell viability rate). These findings support the feasibility of using CH/ABE films as promising candidates for sustained drug delivery systems. The use of plant-based and biodegradable components underscores the potential of this green strategy in pharmaceutical formulations, contributing to sustainable chemistry and reducing the environmental impact in drug delivery applications.