Decomposition and Stabilization of Drugs. XXI. Photodecomposition and Stabilization of Sodium Guaiazulene Sulfonate

Abstract

Photodecomposition and stabilization of sodium guaiazulenesulfonate (I) in aqueous and various organic solvents were studied. It was found that photodecomposition of I was biphasic, and the results fitted the zero-order kinetic pattern.
Further, this photolysis was inhibited by the addition of halogen ions, and univalent and bivalent metal ions.
In the case of replacement with N₂ and the addition of hydroquinone or pyra zoloned erivatives, I was also stabilized. It was found that I formed the charge transfer complex with pyrazolone derivatives, composing of molar 1: 1, which may consequently stabilize the photolysis.