Preclinical Pharmacokinetics of GZK-111, a Dipeptide with Neuroprotective Activity

We studied the pharmacokinetics of GZK-111 (N-phenylacetyl-glycyl-L-proline ethyl ether), a compound with neuroprotective activity, and its metabolite CPG (cyclo-L-prolylglycine) in rat blood plasma after single intravenous and intragastric administration in a dose of 20 mg/kg. It was found that the parent drug undergoes intensive biotransformation; its metabolite CPG persists in the circulation more than twice as long as GZK-111 and its plasma concentrations were higher by 50-70 times than the concentrations of the parent compound.