Formulation optimization of floating microbeads containing modified Chinese yam starch using factorial design

ABSTRACT

Controlled release floating metformin hydrochloride microbeads were prepared and optimized using a blend

of varying concentrations of freeze-dried pregelatinized Chinese yam starch (Dioscorea oppositifolia L) and

sodium alginate. Floating microbeads were prepared by the ionotropic gelation method using 10% w/v

calcium chloride as the cross-linking agent and sodium bicarbonate as the gas releasing agent. A full 32

factorial design was used to investigate the influence of two variables: concentrations of starch (X1) and

sodium bicarbonate (X2) on the swelling, floating lag time and amount of drug released after 1 hour (Q1) and

10 hours (Q10). Potential variables such as the concentrations of drug and total polymer were kept constant.

The results showed that the properties of the floating microbeads were significantly (p