Development and formulation of anti-diabetic capsules containing extract of E. denticulatum: Physicochemical study, encapsulation, and release kinetics

Abstract

Background Eucheuma denticulatum has been widely used to treat diabetes mellitus due to its several antidiabetic components. The current study aimed to formulate capsules containing the crude extract of E. denticulatum. Methods The dry granulation method was used, with microcrystalline starch, corn starch, and the crude extract of E. denticulatum to produce granules. The granules were encapsulated, and the formulations were evaluated for weight uniformity, disintegration time, and in vitro drug release. Results The formulated capsules rapidly disintegrated (≤ 4 min), with a pH of 6.9 ± 0.15, a moisture content of 5 ± 0.01%, and weight uniformity within ±7.5%. Organoleptic and physicochemical properties of the extracts demonstrated their suitability for use in oral capsule formulation. Fourier transform infrared spectroscopy results showed that the active substance and the excipients were compatible. The final formulation spectrum retained most of the characteristic peaks of microcrystalline starch, corn starch, and the extract, but with noticeable shifts in peak positions and variations in intensity, particularly in the O–H, C–O, and C=O vibration bands, which signify that encapsulation of the E. denticulatum extract was successful. In vitro drug release showed almost 98% cumulative drug release and followed non-Fickian (anomalous) transport, Higuchi diffusion, and polymer swelling or erosion. In addition, the encapsulation efficiency was approximately 98%, and the drug-loading capacity was approximately 84%. Conclusion This study has demonstrated that the E. denticulatum capsule has ideal properties, a favorable release profile, and a suitable mechanism for antidiabetic activity. However, this study lacks stability tests and recommends their implementation, which are essential to determine the formulation’s long-term physicochemical stability, potency, and shelf-life .