摘要
硝苯吡啶对光不稳定。本文用紫外光谱法研究该药在不同pH、有机溶剂和抗氧剂作用下的稳定性。硝苯吡啶低浓度时光解反应呈表观一级反应,高浓度时为零级反应;在pH 5～8的范围内较稳定,以pH 6时光解速度最慢;无抗氧剂存在下的光解速度常数是有NaHSO_3或Na_2S_2O_3存在下的1.2～1.3倍。硝苯吡啶在乙醇中光解最快,其次为乙醚,乙酸乙酯,在甲苯中光解最慢。硝苯吡啶在钠光下很稳定,其光解的表观常数K_(表观)为1.442×10^(-2)h^(-1),半衰期t_(1/2)为69.26h。
Nifediine is a photosensitive compound. The stability of the drug in different pH, organic solvents and in the presence of antioxidants was determined spectrophotometrically. The disappearance of nifedipine at lower concentrations was best described by apparent first-order kinetics. At higher concentrations zeroorder kinetics were followed. The drug was more stable at pH 5～8. The rate of photo-oxidation at pH 6 reached a minimun. The rate constant of the aqueous solutions of nifedipine is 1.2～1.3 times as much as that in the presence of NaHSO_3 or Na_2O_3. Nifedipine is photo-oxidized fastest in ethanol, then in ethyl ether and ethyl acetate, and slowest in toluene. Nifedipine is very stable to degradation when irradiated under sodium light. K_(app)=1.442×10^(-2) h^(-1), t_(1/2)=69.26 h.
出处
《中国药科大学学报》
CAS
CSCD
北大核心
1991年第1期1-4,共4页
Journal of China Pharmaceutical University
关键词
硝苯吡啶
稳定性
光降解反应
Nifedipine
Satability
Photochemical degradation
