Ortiz C S, de Bertorello M M
Departamento de Farmacia, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
J Pharm Sci. 1994 Oct;83(10):1457-60. doi: 10.1002/jps.2600831018.
The degradation kinetics of N-(5-methyl-4-isoxazolyl)-4-amino-1,2-naphthoquinone (1) was studied in aqueous solution over a pH range of 0.65-7.50, at 35 degrees C and at a constant ionic strength of 0.5. The degradation rates were determined by high-pressure liquid chromatography and were observed to follow pseudo-first-order kinetics with respect to the concentration of 1. The pH-rate profile was linear with slope -1 under acidic pH, becoming pH independent from 3.50 to 7.50. Good agreement between the theoretical pH-rate profile and the experimental data supports the proposed degradation process. The catalytic rate constants for hydrogen ion and water were kH = 0.901 M-1 h-1 and k0 = 1.34 x 10(-3)h-1, respectively. These data are appropriate to develop a stable dosage form of 1. The accuracy, peak sharpness, and asymmetry factor for the analytical method were determined.
在35℃、离子强度恒定为0.5的条件下，研究了N-(5-甲基-4-异恶唑基)-4-氨基-1,2-萘醌（1）在pH值为0.65 - 7.50的水溶液中的降解动力学。通过高压液相色谱法测定降解速率，观察到其相对于1的浓度遵循准一级动力学。在酸性pH条件下，pH-速率曲线呈线性，斜率为-1，在pH值3.50至7.50范围内与pH无关。理论pH-速率曲线与实验数据之间的良好一致性支持了所提出的降解过程。氢离子和水的催化速率常数分别为kH = 0.901 M-1 h-1和k0 = 1.34×10(-3) h-1。这些数据适用于开发1的稳定剂型。测定了分析方法的准确度、峰尖锐度和不对称因子。
