(585a) The Use of Dynamic Vapor Sorption to Characterize Surface Properties of Amorphous Valnemulin Hydrochloride

Amorphous systems have attracted considerable attention due to their favorable properties; however, their stability issues still pose a major challenge resulting from their strong hygroscopicity. The interaction of vapor with these pharmaceuticals is an important topic, from the aspect of stability as well as processing treatment. Dynamic vapor sorption method is used to characterize hygroscopicity properties of solid powder, especially in the field of pharmaceuticals. In the present investigation we used dynamic vapor sorption to study polar vapor and nonpolar vapor uptake by amorphous valnemulin hydrochloride powder as a function of time and relative humidity. We model the data obtained to suggest sorption mechanisms, which are based on surface adsorption or bulk adsorption. In addition, the surface properties, specific surface area and surface energy are investigated using related equations through dynamic vapor sorption analysis. In conclusion this study allows insights into both vapor adsorption/desorption behavior and surface properties of amorphous valnemulin hydrochloride.