Impact of medication swallowing lubricants on the in vitro dissolution of crushed and whole metformin tablets: dissolution kinetics study.

Metformin is the most common drug used in patients with type 2 diabetes. Our aim is to assess if the in vitro dissolution of Metformin IR 500 mg tablets and its kinetics is altered in the presence of various medication swallowing lubricants used in vivo and to evaluate their rheological properties of tablet lubricant. The dissolution profile of metformin tablets (crushed and whole) mixed with selected medication swallowing lubricants was studied in a Distek® Dissolution apparatus at 6 different time points (n = 5). Samples were diluted and analysed using a UV-visible Spectrometer at a wavelength of 232 nm using a calibrated absorbance-concentration curve. Dissolution data will be modelled to understand the effect on its dissolution kinetics. Rheology studies were completed using an AR G2 System Rheometer. Gloup® Forte delayed the in vitro dissolution of metformin from crushed or whole tablets and produced lower peak concentrations, irrespective of the pH of the dissolution media (reduction up to 35% reduction in concentration in pH = 6.8). Gloup® Forte has changed the release to almost erosion-controlled in different media when mixed with crushed metformin tablets. Further studies evaluating the effects of commonly used thickened fluids on medication may be required to better inform clinical practice.