Formulation and Evaluation of Oseltamivir-Loaded Microbeads

The present study focused on the formulation and systematic evaluation of oseltamivir-loaded microbeads as a novel controlled-release drug delivery system to overcome the limitations of conventional oseltamivir administration. Oseltamivir phosphate, a potent neuraminidase inhibitor used in the treatment and prevention of influenza A and B, but suffers from challenges such as a short half-life, the need for frequent dosing, bitter taste, and poor patient compliance. To address these issues, microbeads were developed using the emulsion gelation method, employing sodium alginate as a biodegradable, biocompatible polymer and calcium chloride as a cross-linking agent. Ten formulations (F1–F10) were prepared by varying the concentration of sodium alginate, while maintaining a constant drug load. The resultant microbeads were evaluated for physicochemical and performance characteristics, including percentage yield, particle size distribution, drug content, encapsulation efficiency, swelling index at two physiological pH values (1.2 and 7.4), in vitro drug release, Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Results showed that polymer concentration had a significant impact on drug encapsulation, swelling behaviour, and release kinetics. Formulation F10 exhibited the highest encapsulation efficiency (83.12%) and swelling index, indicating enhanced mucoadhesive and controlled-release potential. Meanwhile, F1 displayed the highest drug release (96.7%) over 6 hours, making it more suitable for immediate release. FTIR analysis confirmed the chemical compatibility of oseltamivir with sodium alginate, and SEM images revealed uniform, spherical microbeads with rough surfaces, suggesting effective cross-linking and high surface area. The study concludes that oseltamivir loaded microbeads are a promising candidate for achieving sustained drug release, reduced dosing frequency, and improved patient adherence. This delivery system could be particularly beneficial in managing long-term or seasonal antiviral therapy, and may serve as an innovative platform for other short-acting antiviral drugs.