Abstract

Introduction: Controlled drug delivery systems (DDS) are vital for enhancing therapeutic efficacy while minimizing side effects. Alginate (Al)-based materials have emerged as promising candidates due to their biocompatibility, gel-forming capacity, and ease of modification. This study aims to evaluate the performance of five novel Al-based formulations for the controlled rate of spiramycin release.

Methods: Five DDS were developed: spiramycin-Al hydrogel (SAH), spiramycin-acid activated montmorillonite-Al hydrogel (SMAH), spiramycin-polylactide-acid activated MMT-Al hydrogel (SPMAH), and spiramycin-Al aerogel beads and films (SAAB and SAAF). Preparation involved drug encapsulation, incorporation of MMT as a sorbent, calcium chloride-induced crosslinking, coating with polylactide, solvent exchange, supercritical drying, and drug impregnation. In vitro drug release was assessed via dissolution tests, and antimicrobial efficacy was evaluated against E. coli, S. aureus, and E. faecalis.

Results: Among the hydrogel formulations, SPMAH demonstrated the slowest release profile (20%), indicating effective sustained release, while SMAH and SAH showed higher release rates (>21% and >42%, respectively). SAAB and SAAF exhibited faster release in water compared to 50% Glycerol Ringer’s solution. In antimicrobial assays, SAAB showed the most potent inhibition against all tested bacteria, highlighting its potential for effective antimicrobial action.

Conclusion: The results demonstrate that Al-based DDS, particularly SPMAH and SAAF, offer promising platforms for controlled spiramycin delivery. These systems may contribute to combating antimicrobial resistance by enabling sustained and targeted drug release. This study provides new insights into the development of advanced biomaterial-based DDS for antibiotics.