Formulation Development and Evaluation of Hydrogel Based Gastroretentive Drug Delivery System of Antihypertensive Drug

Site specific drug delivery has become the important aspect of research. In present study focused has been made to formulate gastroretentive drug delivery (GRDDS) of drugs having narrow absorption window or having good absorption at proximal part of gastrointestinal tract (GIT) to deliver at stomach site. Hydrogel based gastroretentive formulation of ramipril were prepared by gas blowing technique with the help of using monomers like acrylamide and acrylic acid; bisacrylamide (BIS) as cross linker; pluronic F-127 as foam stabilizer; ammonium per sulphate (APS) as redox initiator; N, N, N’, N’-tetramethylethylenediamine (TEMED) as catalyst and sodium bicarbonate (NaHCO3) as foaming agent. Chitosan was taken as secondary polymer to enhance the mechanical properties of formulation. Hydrogel were characterized with respect to various parameters such as swelling ratio, mechanical strength, apparent density, porosity, void fraction, drug entrapment and in vitro drug release. Further scanning electron microscopy (SEM) and stability studies of formulation were carried out. Study showed the influence of chitosan various concentration on mechanical strength and also on swelling properties. The drug release from chitosan based hydrogel showed for prolonged period of time. Stability studies showed no change in physical appearance and insignificant difference in entrapment efficiency. Thus prepared formulation could be a better targeting for gastroretentive drug delivery.