In vitro investigation of sodium diclofenac adsorption on sucralfate.

Adsorption of sodium diclofenac was investigated in the presence of sucralfate--a cytoprotective agent preventing gastropathy, adverse effect of diclofenac. Evaluation of adsorption was performed by means of a static method in vitro taking into account pH of the environment, temperature, concentration of the investigated agents and the form of sucralfate. Findings obtained prove that sodium diclofenac is adsorbed on sucralfate in all investigated pH ranges and the capability of sucralfate binding depends on its form, temperature and environmental pH. The highest binding was observed at pH 5.0 in the presence of sucralfate, which at this pH has the form of a suspension, while the lowest--at pH 1.5 in the presence of sucralfate in the form of paste. Low values of adsorption temperature of diclofenac as well as the relationship between the level of its adsorption and environmental pH are the dominating factors pointing to the physical and exothermic adsorption.