Applicability of an HPLC System in Stability Studies of a 4-Isoxazolylamino-1,2-Naphthoquinone

CRISTINA S. ORTIZ Y M. M. DE BERTORELLO

DRUG STABILITY

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Año: 1996 p. 123 - 123

high-performance liquid chromatographic assay for the stability study of 2-hydroxy-N-5-methyl-4-isoxazolyl)-1,4-naphthoquinone-4-imine (1) is described. The behavior of 1 was investigated in aqueous solution over a pH range of 1.25 to 11.95 at 35 C and at a constant ionic strength of 0.5. The rate constants and half-lives were calculated from concentrations of compound 1 obtained at various time intervals. Pseudo-first-order kinetics with respect to the concentration of 1 were observed throughout the pH range studied. The decomposition showed specific ion catalysis at pH < 4 and specific hydroxide ion catalysis at pH < 10. The pH range of maximum stability was between about 5 to 9 with the lowest estimate (3.73 x 10 being observed at pH 4.95.