5-Styryl-4,5-cis-1,3-oxazole-2-one-4-car-boxylic acid (CDRI-85/92) is a new proton
pump inhibitor presently in advanced stage of preclinical trials as antiulcer pharmacophore.
Since proton pump inhibitors are prodrugs requiring activation in acid environment,
an ester prodrug of CDRI-85/92 was also synthesized. In view of the importance, a
pharmacokinetic study of CDRI-85/92 and its ester prodrug was conducted after oral
doses in rats. Following a 20 mg/kg oral dose of CDRI-85/92, the compound was detectable
in the serum samples up to 24 h with a maximum serum concentration (Cmax) of 1 838.40 ± 101.16 ng/ml at 1.5 h and an elimination half-life of 4.96 h, whereas,
multiple Cmax values of CDRI-85/92 were observed with oral doses (equivalent to 20 mg/kg of CDRI-85/92)
of the ester prodrug of the compound. All the three Cmax values of the compound were lower than that after oral dose of CDRI-85/92. The compound
was eliminated slowly from serum with an elimination half-life of 5.14 h. Moreover,
the systemic availability of CDRI-85/92 also decreased from 6111 to 3 463 ng · h/ml
after the ester prodrug administration. The decrease in systemic availability of CDRI-85/92
could be due to its higher clearance after its ester prodrug administration.
Key words
CDRI-85/92, HPLC, pharmacokinetics, prodrug, rat - Proton pump inhibitor - 5-Styryl-4,5-cis-1,3-oxazole-2-one-4-carboxylic
acid