Advances in cardiac nursing practice

RG 12915 (I) undergoes dechlorination and substitution in aqueous solutions when exposed to an artificial daylight fluorescent light. The free-radical photodecomposition exhibits apparent first-order kinetics at all concentrations and the reaction proceeds faster in dilute solutions. The drug substance is also susceptible to oxidative degradation. Oxidation occurs on the benzofuran moiety as well as on the quinuclidine moiety. Auto-oxidation on the benzofuran moiety produces a corresponding hydroperoxide. Subsequent decomposition of the hydroperoxide gives rise to the secondary oxidation product, the hydroxy compound. The oxidative free-radical reaction shows an induction period, followed by a period of accelerating degradation and eventual leveling off. The oxidation reaction proceeds faster in concentrated solutions and at lower pH, and is accelerated by cupric ion. EDTA prevents the oxidative degradation of the drug substance. Propyl gallate inhibits the oxidation of the benzofuran moiety but not N-oxide formation.