Formulation and In vitro Characterization of Floating Gel Beads of Metformin Hydrochloride

A floating type dosage form, gel beads of metformin hydrochloride was prepared by emulsification gelation technique. The gel bead was formed by mixing the polymer in water, oil phase and it was extruded in the calcium chloride solution as curing agent. The formulation parameters optimized were polymer ratio, concentration of oil, curing time on drug content, floating lag time, morphology, swelling of beads and release kinetics.The scanning electron photomicrographs revealed morphology of beads. The size of beads was measured. Entrapment efficiency of drug loaded beads was found to be over 90%. In vitro release of metformin hydrochloride from alginate–pectin beads into simulated gastric fluid at 37 ºC showed no significant burst effect. The cumulative release reached above 74.71 ± 4.15% in about 12h. The use of sodium alginate and combinations of sodium alginate with pectin were used to study the effect on the sustained release of the drug from the formed beads. It was found that sodium alginate was not sufficient to sustain the drug release at gastric pH (fed condition). Appropriate combination of alginate and pectin could provide the sustained release of drug. Floating gel beads formulation provides an alternative delivery for metformin in diabetes treatment.