D. Pretzer, A. Repta
Aug 1, 1987
Citations
0
Influential Citations
2
Citations
Journal
International Journal of Pharmaceutics
Abstract
The degradation of [[(4-methoxyphenyl)sulfonyl]hydrazono]acetic acid (NSC-267213) was studied in buffered aqueous solution at pH 1.0–9.0. Degradation occurred rapidly with t90 < 10 min at all pH values studied. Apparent first-order kinetics were observed at pH ≥ 6.0 while at pH ≤ 5.0 the loss appeared biphasic. The major degradation products observed at pH ≥ 6.0 were 4-methoxyben-zenesulfinic acid and glycolic acid. In addition to these products, at pH ≤ 5.0, 4-methoxybenzenesulfonylhydrazide, glyoxylic acid and the isomer of the starting compound were also detected. These products and the kinetic behavior were accounted for by a degradation mechanism involving hydrolysis and isomerization equilibria and elimination of sulfinate from the hydrazone. At pH ≥ 6.0, decomposition occurred only via the elimination mechanism. At pH ≤ 5.0, hydrolysis and isomerization equilibria affected levels of the hydrazone, however, its irreversible loss was attributable to the elimination mechanism.