Impact of mixed counter ion on saturation solubility of esylate salt of a weak basic drug to formulate physically stable and non-hemolytic ready to use injectable solution.

Current work investigates a typical issue in formulating a physically stable solution especially when more than one counter ions exist in the composition. The impact of different counter ions on solubilization of monohydrate esylate salt of a free base GSK-497,[BH:CHSO:HO] (1:1) (pKa value 8.0) was investigated to formulate ready to use small volume injectable solution.