Using The Box–Behnken Experimental Design Development of Gastroretentive Mucoadhesive Microspheres of Simvastatin by Spray Drying Method

Simvastatin is an antihyper-lipidemic drug which inhibits HMG-CoA reductase, interrupting cholesterol synthesis. It is poorly water soluble drug having very low bioavailability (5%). It is having better absorption in upper gastro intestinal tract. Due to lower bioavailability and short biological half-life simvastatin is prescribed 2-3 times a day which leads to lower patient compliance. The aim of the present work was to prepare controlled release microspheres which and retained in the gastric area by adhering to the mucosal membrane for longer period of time. It was a also proposed to design and optimize the formulation and process parameters for preparation of gastroretentive simvastatin microspheres using spray drying technique. The major problem associated with oral drug delivery is ineffective absorption and low bioavailability because drugs having narrow absorption window. Simvastatin microspheres was prepared using polymer HPMC K4M as carrier polymer and Eudragit RSPO were prepared using spray drying technique. The in vitro evaluation of mucoadhesive property of simvastatin microspheres was done on goat intestinal mucosa which showed strong mucoadhesion of 85% up to 6 hours. The in vitro drug release studies of microspheres were performed in 0.01 M sodium phosphate containing 0.5% SLS using syringe pump for 8 h.