Formulation and Evaluation of Gastro-Bilayer Floating Tablets of Ezetimibe as Immediate Release Layer and Atenolol as Sustained Release Layer

Abstract:

Introduction: Combination therapy of ezetimibe and atenolol is highly desirable for better management of dyslipidaemia and hypertension. Ezetimibe has poor solubility hence variable and low bioavailability. Atenolol has poor absorption in lower gastrointestinal tract, short half-life. Therefore, the present study was to develop gastro-bilayer floating matrix tablet in which ezetimibe was incorporated as immediate layer and atenolol as sustained release layer. Methods: Solubility of the ezetimibe was enhanced by solid dispersion technique and was characterized by FTIR, DSC and XRD study. Gastrobilayer floating tablets were prepared by direct compression method. Results and Discussion: Hydroxypropyl methylcellulose K100 (37.5 % w/w) as release retardant and croscarmellose sodium (15 % w/w) as superdisintegrants in immediate layer as optimized. The total floating time of the optimized tablet was 12 h with 9 min of floating lag time. Atenolol release was sustained through diffusion mechanism over 12 h and more than 95 % ezetimibe was released within 30 min. Conclusion: It can be concluded that 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.

Key words: Gastro-bilayer, Floating, Immediate release, Sustained release, Ezetimibe, Atenolol.