Journal of Pharmaceutical and Biomedical Analysis 2002-11-07

Photostability profiles of the experimental antimetastatic ruthenium complex NAMI-A.

Marjan Bouma, Bastiaan Nuijen, Martine T Jansen, Gianni Sava, Auke Bult, Jos H Beijnen

Index: J. Pharm. Biomed. Anal. 30(4) , 1287-96, (2002)

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Abstract

NAMI-A is a novel ruthenium complex with selective activity against metastases currently in Phase I clinical trials in The Netherlands. The photostability of this new agent in solid state and in solution has been investigated utilizing a stability-indicating reversed-phase high performance liquid chromatographic (HPLC) assay and ultraviolet/visible (UV/VIS) light spectrophotometry. In solid state, NAMI-A proved to be photostable. In solution, however, the compound degraded rapidly, in a pH-independent manner in the pH range of 2-5. At alkaline pH, the degradation rate was higher than at acidic pH. The type of buffer species had little influence. NAMI-A concentration was inversely related to the photostability. Addition of photostabilizers (5% DMSO, 2% benzyl alcohol, 0.001% curcumin) marginally increased the half-life. NAMI-A's photostability in solution was influenced to the greatest extent by addition of an alcohol, with the least polar solvent system (50% propylene glycol) providing the most stable medium. Based on the presented results, it is recommended to store NAMI-A solutions in the dark.