Stability of ciprofloxacin in 5% dextrose and normal saline injections.

The stability of ciprofloxacin in 5% dextrose and normal saline i.v. admixtures have been determined using a stability-indicating high performance liquid chromatographic assay method reported in the literature. The solutions were stored in plastic bags, a procedure being used in hospitals for in or out-patient therapy. The solutions were stable for at least 3 months when stored at room or refrigerator temperatures. They remained clear throughout the study and their pH values did not change. The expiry date recommended by the manufacturer appears to be very conservative from a chemical viewpoint.

Stability of cefuroxime axetil in suspensions.

Cefuroxime axetil is a mixture of two equally active isomers (50% each). A stability-indicating high-pressure liquid chromatography method for the quantification of cefuroxime axetil has been developed. The method is accurate, precise and reproducible. The percentage, relative standard deviation based on six injections was 1.2. Using the developed method, the chemical stability of cefuroxime axetil suspensions has been determined in three vehicles containing sugar and two without sugar. The results varied widely in the vehicles without sugar (up to +/- 31%). In the viscous vehicles containing sugar, the variations in the results were only up to +/- 6%. The cefuroxime axetil in these suspensions was stable up to 28 days when stored at 5 degrees C. In addition, pH values were stable and the physical appearances of the samples did not change.

Chemical stability of cefotetan disodium in 5% dextrose and 0.9% sodium chloride injections.

The chemical stability of cefotetan disodium in 5% dextrose and 0.9% sodium chloride injections has been studied using a stability-indicating high-pressure liquid chromatographic (HPLC) assay method. The drug appears to be relatively unstable at 25 degrees C (expiry time 2 days), compared with at least 41 days at 5 degrees C and at least 60 days at -10 degrees C. Thawing the frozen samples in a microwave (90 s) did not cause any significant decomposition. The manufacturer's recommended expiry time of 4 days at 5 degrees C and at least 7 days at -10 degrees C is very conservative. The HPLC method developed is accurate and precise with a relative percentage standard deviation of 1.7 based on six readings. The method appears to be stability-indicating as the samples decomposed under drastic conditions had almost no drug left and new peaks were observed in the chromatograms.