Understanding the Effect of pH on Solubility of Gamavuton-0 in The Aqueous Solution: Expreimental and COSMO-RS Modelling
Abstract
the drug delivery and development. Especially, for the pharmaceutical compound that have varied solubility
values in the aqueous solution with diverse pH condition. In this work, the solubility of newly
synthesized pharmaceutical compound, namely Gamavuton-0 (GVT-0) in aqueous solution at four
different pH ¼ (2, 4, 6, and 8), within temperatures T ¼ (300.15, 305.15, 310.15, and 315.15) K and atmospheric
pressure (p ¼ 0.1MPa) were determined through experiment and computational modelling
approaches. The experimental measurement showed that (i) the solubility increased with increasing the
temperature and (ii) the solubility decreased from pH 2 to 4 and increased from pH to 4e8. The same
trend of GVT-0 solubility in the studied pH of the aqueous solution was also observed from the
computational modelling using Conductor-like Screening Model for Real Solvent (COSMO-RS). According
to this model, there are three different GVT-0 species exist in aqueous solution at different pH: (1) The
protonated form that exist as major species at pH 2, (2) neutral GVT-0 exist as main component at pH 4
and 6, and (3) the deprotonated form presents as primary species at pH 8. The equilibrium between the
protonated e neutral e deprotonated of GVT-0 species responsible for their solubility in the aqueous
solution in different studied pH condition. The solubility results of this study could be useful the
formulation and development of GVT-0.