Formulation development and evaluation of floating microspheres of drotaverine hydrochloride as gastroretentive dosage form

Abstract

The aim of the current research work is to formulate and characterized the floating microspheres of drotaverine hydrochloride (DRH). DRH is an antispasmodic drug which has a short residence in the intestine during diarrhoea that prompts poor bioavailability and frequent dosing. Microspheres were prepared by solvent evaporation technique by using polymers such as ethyl cellulose and HPMC. Floating microspheres prepared by using Design-Expert® version13 software with 3² full factorial designs. Further, microspheres were evaluated for flow characteristics, entrapment efficiency, % yield, particle size analysis, % buoyancy, zeta potential analysis, scanning electron microscopy and in-vitro drug release. In vitro, drug release studies were carried out in a 0.1N HCl solution. Micromeritics studies showed good flow properties and maximum entrapment efficiency was found to be 84.83%. The microspheres were spherical in shape with distinct pores, observed under scanning electron microscopy. The in vitro buoyancy was found to be in the range of 69.23%–84.72% and a total buoyancy time of more than 10 ​h. Results clearly stated that DRH floating microspheres were safe and effective drug delivery over an extended period which can increase bioavailability, and patient compliance, and decrease dosing frequency.