Formulation Optimization of Metformin-Loaded Propyl Moringa Gum Beads

The purpose of the present work was to optimize the formulation of extended-release, metformin-loaded ionically-gelled propyl Moringa gum beads.

The metformin-loaded beads of propyl Moringa gum were prepared by ionotropic gelation method employing calcium chloride as a cross-linking agent. A three-factor three-level central composite experimental design was applied to obtain the optimized batch of beads with maximum %yield, drug entrapment and extended-release over 24 h. The optimized batch of beads was characterized by Fourier-transform infra-red spectroscopy, X-ray diffraction, scanning electron microscopy, swelling, and mucoadhesive behavior.

The optimized batch of beads contains propyl Moringa gum – 5.916 (%w/v), calcium chloride – 11.779 (%w/v), and metformin – 25 mg. The % yield and drug entrapment efficiency of polymeric beads were found to be 124.31% and 62.83% respectively. X-ray diffraction patterns revealed the crystalline behavior of an optimized batch of metformin-loaded propyl Moringa gum beads. The scanning electron micrographs demonstrated the oblong-shaped and granular surface of polymeric beads. The optimized batch of polymeric beads exhibited pH dependent release with faster release in distilled water, pH 1.2, and 4.5 medium while sustained release at pH 6.8. The beads also showed good ex vivo mucoadhesive properties.

The optimized batch of ionically gelled propyl Moringa gum beads showed excellent potential for extended-release formulation of metformin. However, further in vivo studies are needed to explore its commercial potential.