Preparation and evaluation of floating risedronate sodium-Gelucire 43/01 formulations

Single and multi-unit floating matrices of risedronate sodium were prepared using Gelucire 43/01 by melt solidification and melt granulation technique, respectively. The controlled release floating matrices were evaluated for in vitro and in vivo floating ability and in vitro drug release. Effect of aging on Gelucire 43/01 was evaluated by hot stage microscopy (HSM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), in vitro floating ability, and in vitro drug release. Multi-unit system obtained has shown initial burst release, which was suppressed in single unit system. Both single- as well as multi-unit systems showed increase in rate of drug release on aging due to changes in the properties of the Gelucire 43/01. Multi-unit matrices obtained by melt granulation were relatively easier for scale up and advantageous if the initial burst release does not cause any significant clinical adversity.