Sylvestri M F, Makoid M C, Cox B E
School of Pharmacy and Allied Health Professions, Creighton University, Omaha, NE.
Am J Hosp Pharm. 1988 Jun;45(6):1353-6.
The stability of cephalexin monohydrate suspension in plastic oral syringes was studied. Commercially available cephalexin monohydrate powder for oral administration was reconstituted according to the manufacturer's instructions and stored in the original containers or drawn into 5-mL clear polypropylene oral syringes. The original containers and syringes were divided into groups and stored at -20, 4, 25, 40, 60, or 80 degrees C. Powder from two additional lots was similarly reconstituted and packaged; these original containers and syringes were stored at 80 degrees C only to assess interlot variability. Immediately after reconstitution and at specified times during storage, three syringes and the corresponding three original containers stored at each temperature were removed, and their contents were analyzed for cephalexin concentration using the standard USP iodometric assay for antibiotics. The stability-indicating nature of the assay was documented. Cephalexin monohydrate followed a first-order rate of degradation at temperatures of 40, 60, and 80 degrees C. At temperatures of -20, 4, and 25 degrees C, cephalexin monohydrate exhibited no appreciable degradation during the 90-day study period. Cephalexin monohydrate suspension reconstituted from powder as a suspension and repackaged in clear polypropylene oral syringes was stable for 90 days when stored under ambient, refrigerated, and frozen conditions.
对头孢氨苄一水合物混悬液在塑料口服注射器中的稳定性进行了研究。将市售的口服头孢氨苄一水合物粉末按照制造商的说明进行复溶，并储存在原容器中或吸入5毫升透明聚丙烯口服注射器中。将原容器和注射器分成几组，分别储存在-20、4、25、40、60或80摄氏度下。另外两批粉末也同样进行复溶和包装；这些原容器和注射器仅在80摄氏度下储存以评估批次间的变异性。复溶后立即以及在储存期间的指定时间，取出在每个温度下储存的三个注射器和相应的三个原容器，并使用美国药典标准碘量法抗生素测定法分析其内容物中的头孢氨苄浓度。记录了该测定法的稳定性指示特性。头孢氨苄一水合物在40、60和80摄氏度下遵循一级降解速率。在-20、4和25摄氏度下，头孢氨苄一水合物在90天的研究期间没有明显降解。由粉末复溶成混悬液并重新包装在透明聚丙烯口服注射器中的头孢氨苄一水合物混悬液，在常温、冷藏和冷冻条件下储存时90天内稳定。
