Cefepime is a type of cephems used to treat various infections. According to the United States Pharmacopeia and the National Formulary (USP 42-NF 37*), "IMPURITIES: Limit of N-Methylpyrrolidine" for "Cefepime for Injection" should be carried out with a 4.0 mm (I.D.) x 25 cm (length) column filled with L76 packing material. Use of two IC YK-421 columns, 4.6 mm (I.D.) x 12.5 cm (length) each, filled with L76 packing material in series confirmed the requirement was met. In addition to the method validation, a commercial cefepime dihydrochloride for injection was analyzed using the method. The concentration of N-methylpyrrolidine found was 0.09%, confirming the detected amount was below the allowable limit (1.0%). In this method, cefepime elutes around 50 minutes. It is detectable by a UV detector, but rarely detected by a CD detector. It is noteworthy that using one YK-421 column alone fulfills the system suitability requirement and it is applicable for the quantification of N-methylpyrrolidine in commercial cefepime injections.

System suitability requirementRelative standard deviation (RSD) (Standard solution): ≤ 4.0%

*The version at the time of the application acquisition. 

Sample: 10 µL each
(Sample solution) Commercial Cefepime hydrochloride formulation equivalent to 5 mg/mL of Cefepime hydrochloride in 0.002 N HNO₃ aq.
(Standard solution) N-Methylpyrrolidine 0.05 mg/mL in 0.002 N HNO₃ aq.

1. 1.N-Methylpyrrolidine