Investigation Of Stability Of Cefepime In Arnidazole And Sodium Chloride Injection By Means Of Spectrophotometry

Aim: To probe the stability of cefepime in ornidazole and sodium chloride injection, so as to provide useful information for its clinical application.Methods: The contents of cefepime in ornidazole injection were determined by ultraviolet spectropotometry. According to the absorption curve of the two drugs, the content of cefepime was determined by K-ratio spectrophotometry, ornidazole by dual wavelength spectrophotometry . cefepime solution(20μg/ml) and ornidazole solution(20μg/ml) were prepared in distilled water, their absorption spectrum was obtained by scanning in the range of 200-400nm, showingλmax of cefepime and ornidazole were 257nm and 319nm respectively. By linear regression of ?A vs C, the standard curve linear equation could be foumd. By imitating clinical settings, 1g cefepime was added to 100ml of 0.5% ornidazole and sodium chloride injection, then the contents of the two drugs were measured, respectively, at 0,1,2,4,6 hour post preparation, while observing whether or not any change in the uv absorption curve and precipitate, air bubble and color occurred. Based on the C-t plot, logC-t plot, 1/C-t plot, the cefepime was judged as the first-order kinetics and thereby the degradative rate constant(k) at 40℃, 50℃, 60℃, 70℃could be calculated and activated energy(E) could be calculated using Arrhenius equation. Finally, the k, t0.9, t0.5 could be yield at any temperature.Results:Validation of methodology showed the method developed by us had high precise and recovery. There are no evident variation in content during 6 hours at room temperature. The average recovery rates of cefepime and ornidazole were 100.67%and 99.40%(n=5). k is 0.0313,...