Formulation and Optimization of Monolithic Fixed-Dose Combination of Metformin HCl and Glibenclamide Orodispersible Tablets

The treatment of type II DM involves the use of combination of drugs, especially at the chronic stage. However, the pill burden of this combination therapy combined with swallowing difficulties, occurring at a later stage of DM, has been the major challenge for successful treatment outcomes. This study was aimed at formulating and optimizing a monolithic fixed-dose combination (FDC) of metformin (MET) and glibenclamide (GLB) orodispersible tablets (ODTs) to overcome both the pill burden and swallowing problems. The FDC ODTs were prepared by the melt granulation technique using polyethylene glycol (PEG) 6000 as a binding agent and crospovidone as a superdisintegrant. In the preliminary study, the effects of sodium lauryl sulphate (SLS), PEG 6000, crospovidone, and compression force on friability, disintegration time, and drug release of tablets were investigated. The FT-IR studies showed that there were no incompatibilities between MET and GLB as well as within excipients. The preliminary studies revealed that PEG 6000 and compression force significantly affect both the friability and the disintegration time, while SLS and crospovidone only affect the disintegration time. Therefore, the effects of PEG 6000, crospovidone, and compression force were further studied and optimized using the central composite design. Accordingly, the most desirable optimal values were obtained at 3.82% of PEG 6000, 9.83% of crospovidone, and 10.6 kN compression force having a friability of 0.302% and a disintegration time of 18.7 seconds. From these results, it can be concluded that a monolithic FDC of MET and GLB ODTs having adequate mechanical strength and faster disintegration time was successfully formulated.