Formulation and Evaluation of Biphasic Gastro Floating Tablets of Nateglinide and Atenolol

Abstract

The aim was to design, formulate, and evaluate bilayer gastro floating tablets of an antidiabetic agent, nateglinide (immediate-release layer), and antihypertensive agent, atenolol (sustained-release layer). The solubility of model drug nateglinide was enhanced by using cremophor RH 40 and characterized by FTIR, DSC, XRD, SEM, and in vitro dissolution. It was found that selected ingredients were compatible, and crystalline nateglinide transits to an amorphous state. The gastro-bilayer tablets were directly compressed using the optimized nateglinide (solid dispersion equivalent to 60 mg of nateglinide) immediate-release layer (IRL2) containing different percentage of F-Melt type C and crospovidone and atenolol (50 mg) sustained-release layer (SRL6) using different percentage of HPMC K15, sodium bicarbonate, and MCC. Developed tablets were evaluated and found within the acceptance range as per the guidelines. The release of nateglinide and atenolol from an optimized bilayer tablet (BLT3) was 100 % within 60 min and 12 h, respectively. The floating lag time and total floating time were 2 min and 12 h, respectively. The atenolol sustained-release followed the diffusion mechanism. The combination of nateglinide and atenolol was successfully showed a biphasic release pattern. This formulation may strengthen the fixed-dose combination therapy for diabetes and hypertension at a low cost.