Date Mucilage as Co-Polymer in Metformin-loaded Microbeads for Controlled Release

Abstract

Date mucilage (Phoenix dactylifera) was characterized and evaluated for use as a polymer in controlled release metformin-loaded microbeads. Date mucilage was characterized using proximate composition and elemental analysis. Metformin-loaded (1% w/w) microbeads were formed by the ionotropic gelation method using blends (2 % w/v) of date mucilage: sodium alginate in varying concentrations (20:80 C4, 25:75 C3, 33:67 C2, 50:50 C1) with zinc chloride (10 %w/v) as crosslinking agent. Bead size and morphology; swelling index; entrapment efficiency and release properties were used as assessment parameters for the microbeads formed. The dissolution profiles were fitted to kinetic equations to determine the kinetics and mechanism of drug release while the similarity factor, ƒ2 was used to determine formulations with similar drug release pattern. The results showed that date mucilage has crude fat content of 2.5 % and is devoid of heavy metals. Microbeads formed were spherical with bead size range 0.44–1.99 mm except that prepared from blend C4 that was ellipsoid. Drug entrapment efficiency ranged between 25.0–91.1 %w/w with alginate alone giving the least entrapment. Microbeads formulated with blends C2 and C3 had the slowest dissolution times with t15 24 h. Similarity factor, ƒ2 showed comparable release profiles between C2 and C3 (ƒ2=94.2). Date mucilage thus showed potential as a polymer in the formulation of controlled release metformin-loaded microbeads.