Formulation and Evaluation of Gastro-bilayer Floating Tablets of Simvastatin as Immediate Release Layer and Atenolol as Sustained Release Layer
Department of Pharmaceutical Technology, Maharajah’s College of Pharmacy, Vizianagaram-535 002, India
Department of Pharmaceutical Technology, Maharajah’s College of Pharmacy, Vizianagaram-535 002, India E-mail: [email protected]
Combination therapy is highly desired to deliver atenolol and simvastatin for dyslipidemia and hypertension for concomitant drug treatment. On other hand, atenolol has poor absorption in lower gastrointestinal tract, short half-life and simvastatin has poor solubility. Therefore, the present study was to develop gastro-bilayer floating matrix tablet in which simvastatin was incorporated as immediate layer and atenolol as sustained release layer. Gastro-bilayer floating tablets were prepared by direct compression method and optimized using hydroxypropyl methylcellulose K100 (37.5%) as release retardant and sodium bicarbonate as a gasforming agent. The immediate release layer comprised sodium starch glycolate as superdisintegrant. The tablets of optimized formulations floated on the test medium for more than 12 h with 9 min of floating lag time. Atenolol release was sustained for 12 h via diffusion mechanism and more than 96% release of simvastatin within 15 min was achieved. It can be concluded that, the biphasic drug release pattern was successfully achieved through the formulation of gastro-floating bilayer tablets in this study, allowing strengthened combination therapy for hypertension and dyslipidemia.