Solubility and stability of indomethacin in sodium acetate solution. A consideration of hydrotropic mechanism.

The effect of sodium acetate on the aqueous solubility of indomethacin was studied. Increases in solubility were associated with the presence of sodium acetate in the dissolution medium. The mechanism of solubilisation was considered in relation to the possible effects of highly water-soluble substances on the structure of water. Thermodynamic conditions associated with the interactions were found to be favourable to the proposed mechanism. However, indomethacin was hydrolytically unstable in the solubilised state.