Esters of cephalosporins. Part IV. Hydrolysis of 1-acetoxyethyl ester of cefuroxime in vitro and in vivo.

Hydrolysis of 1-acetoxyethyl ester of cefuroxime [I] in blood was studied in vitro and in vivo. In vitro [I] hydrolyzes to biological active cefuroxime [II] and at the same time it undergoes isomerization to isomer delta 2 of 1-acetoxyethyl ester of cefuroxime [IV] and next hydrolyzes to biological inactive isomer delta 2 of cefuroxime [V]. As a result of hydrolysis [I] in vivo only [II] is formed.