High performance liquid chromatographic determination of cephradine in human plasma and urine

Abstract

Cephradine (CED) and cephalexin (CEX) which is an impurity in CED products, were separated from regular components of plasma and urine on a reversed phase C18 column using sodium heptylsulfonate as an ion-pairing agent, and detected at 260 nm. The limits of accurate determination of CED and CEX in plasma were 100 ng/ml. The precision (relative standard deviation) was of the order of 2.03% (n = 5) at a CED concentration of 1.0pg/ml in plasma. CEX content in commercial CED capsules was determined by the proposed method. It was found that a CED capsule contained 2.88% of CEX. The pharmacokinetic behavior of CED and CEX after an oral administration was discussed using the moment analysis method. The results revealed that CED had almost the same bioavailability as CEX, and the coexistence of CEX in commercial CED capsules had no influence on the pharmacokinetic feature of CED. © 1986, The Japan Society for Analytical Chemistry. All rights reserved.