Development and in Vitro Evaluation of Multi/bi-bilayer Tablet Dual-release Formulations of Vildagliptin and Dapagliflozin for the Treatment of Type 2 Diabetes Mellitus

Introduction: This study aimed to develop an innovative bilayer tablet formulation of dapagliflozin and vildagliptin to increase therapeutic outcomes and patient compliance in diabetes management. Methods: By employing wet granulation, immediate-release, and sustained-release layers were formulated using various super-disintegrating and release-retarding agents, respectively. Several pre-compression parameters were utilized, such as Carr’s index, Hausner ratio, physical attributes (weight variations, friability, hardness), and disintegration time. Drug-excipient interactions were determined through employing FTIR, SEM, DSC, and TGA. In-vitro dissolution studies were performed to assess the release kinetics of these formulations. Results: For immediate-release dapagliflozin, our earlier study demonstrated that the formulations showed Carr’s index (23.5-33.3), physical attributes (weight (145–155 mg), thickness (4.42 ± 0.04 -4.46 ± 0.05 mm), hardness (3.7-5.6 kg/cm2), friability (<1%), and optimized rapid dissolution (F1: 80.50% ± 5.2 in 30 minutes). For sustained-release vildagliptin, the formulations showed Carr’s index (10.48-20), physical attributes (weight (194-203 mg), thickness (3.32 ± 0.06-3.33±0.04 mm), hardness (4.8 ± 0.1-7.6 ± 0.2 kg/cm2), friability (<1%)), and optimized controlled release (A5: 81.76% ± 2.4 in 360 minutes). The results found that F1 and A5 were the optimum formulation for the immediate release of dapagliflozin, and the sustained release of vildagliptin, respectively, and BT-1 was the optimum bilayer tablet because of its rapid onset of action for dapagliflozin (84.23% within 60 minutes) and sustained release for vildagliptin (80.026% within 360 minutes). Conclusion: Based on these data, the optimized bilayer tablet holds the potential to be a convenient and effective treatment option. Further, in-vivo assays are necessary to confirm its efficacy and safety.