Based on the large number experiments on solubilization of poorly water- soluble drugs, the author is of the opinion that hydrotropy is another type of cosolvency and all water soluble substances whether solids, liquids or gases have solubilizing properties. Therefore, aqueous solutions containing small quantities of several water-soluble excipients giving a concentrated solution, may act as a solvent system for some poorly water-soluble drugs. This is one of the concepts of mixed-solvency. This same concept has been explored to formulate the syrups (solutions) of poorly water-soluble drug tinidazole (as a model drug). For this, the blends containing solubilizers from the category of hydrotropes, co solvents and water soluble solids were employed. The blends of randomly selected solubilizers were used for solubility studies. Based on the solubility studies, few blends showing largest solubilities were employed to make the syrup. This may reduce the individual concentration of solubilizers and so reduce their potential of toxicities. The formulated syrups were subjected to accelerated stability studies and they were found quite stable.
