In Vitro Evaluation of Bilayer Tablets Comprising Immediate Release Canagliflozin and Sustained Release Vildagliptin

Abstract

Type 2 diabetes mellitus (T2DM) accounts for about 90–95% of total diabetic cases which can be sustainably maintained by combined therapy. The goal of this study was to develop a bilayer tablet (BLT) that combines sustained release (SR) vildagliptin and immediate release (IR) canagliflozin to improve the treatment outcomes. Nine canagliflozin and six vildagliptin formulas formulas were tested. To determine the most appropriate formulations, the tablets’ physicochemical characteristics—hardness, friability, disintegration, and dissolution—were assessed. The in-vitro drug release study of BLT was conducted using 0.1 N HCl and pH 6.8 phosphate buffer (2 and 4 hours, respectively). For stability and compatibility tests, DSC, FTIR, SEM, and TGA were employed. F4 (74.60% release within 60 minutes) and A5 (89.76% release over six hours) were selected as IR and SR for BLTs. The physical parameters of the BLTs were within the permissible range, with an average weight of 381 mg, weight variability of 4.93%, thickness of 5.40 mm, hardness of 6.2 kg, friability of 0.32%, and a disintegration time of 18.2 minutes. The final bilayer tablet showed 81.34% release of canagliflozin within 1 hour and >80% release of vildagliptin within 6 hours, while no instability cases were recorded. The designed formulations revealed accepted in-vitro performance. Further development and in-vivo tests should be performed to ensure the desired outcomes.

Dhaka Univ. J. Sci. 74(1): 127-137, 2026 (January)