Effects of Thickening Agents Used in Dysphagia on the In Vitro Dissolution of Gliclazide

Dysphagia is common among older adults and frequently necessitates the use of thickening agents to facilitate safe swallowing of medicines, which may in turn alter their bioavailability. This study investigated the impact of two commercially available lubricants—Gloup® Forte and extremely thick water—on the in vitro dissolution behaviour of immediate-release gliclazide tablets. Dissolution studies were conducted using crushed and whole tablets in different media consisting of reverse osmosis water, phosphate buffer (pH 6.8), and 0.1 N HCl at 37 °C. Dissolution profiles were compared using similarity factor (f2) analysis and modelled using established kinetic equations. Gliclazide dissolution was significantly delayed in the presence of Gloup® Forte across all media for both crushed and whole tablets, with f2 values below 50, indicating dissimilar profiles. Dissolution kinetics confirmed that mixing the formulated gliclazide with Gloup® Forte delayed the release and reduced the dissolution rate constant for drug from both crushed and whole gliclazide tablets in media studied.