Fabrication, Optimization and Characterization of Floating Microspheres of Quinapril Hydrochloride using Factorial Design Method

The majority of formulations are available as oral dosage forms. In spite of some pharmaceutical challenges, this route is considered as most suitable way of drug delivery. For that reason it is necessary to optimize dose and dosing frequency to reduce the toxic effects of drug. Therefore, in this study, we have conceptualized the fabrication of floating microspheres of Quinapril Hydrochloride by the solvent evaporation technique with varying ratios of HPMC, Carrageenan, and Poly methyl methacrylate with polyvinyl alcohol that will augment its gastric retention time in conjunction with the sustained pharmacological activity. The formulation process of floating microspheres was optimized for stirring speed (X1) and concentration of polymer ratio (X2) on dependent variables such as percentage entrapment efficiency (Y1), percentage yield (Y2), in vitro buoyancy (Y3), and percentage of drug release (Y4) by using the factorial design. The drug was characterized by Fourier transform infrared spectroscopy, Differential scanning calorimetry was used for the identification of drug polymer blend interaction. The prepared microspheres were characterized by number of parameters including; scanning electron microscopy, percentage yield, particle size, in vitro buoyancy, drug entrapment efficiency, in vitro drug release, and in vivo floating behavior in albino rabbits. The release profile of microspheres prepared with hydrophilic, pore forming material and ion exchange resin combinations was dependent on the layer of pores developed by the fluid present at the absorption site of stomach and the drug release rate was retarded at site of action i.e. GIT.