[CAS NO. 116649-85-5]  Ramatroban

In hypercholesterolemic rabbits, ramatroban prevents macrophage infiltration through MCP-1 downregulation and neointimal formation after balloon injury and attenuates vascular response to acetylcholine. The pharmacokinetic parameters after single oral administration of 75 mg ramatroban were studied in fasting healthy adult volunteers: relative bioavailability of ramatroban tablets (as compared with aqueous solution) was 80.3%. The pharmacokinetics of ramatroban at doses ranging from 25 to 150 mg was found to be linear. When a single dose of 50 mg of ramatroban was given orally to healthy volunteers postprandially, the AUC was 88.8% of that obtained in fasting state. A low total body clearance of ramatroban is shown in elderly subjects; After oral administration of [14C]ramatroban to male rats, maximum concentrations of radioactivity were higher in liver, kidneys and adipose tissues than in plasma. Other organs tissues had lower radioactivity levels than plasma. Radioactivity levels in most organs tissues declined in parallel with the decrease in the plasma radioactivity. In contrast, elimination of the radioactivity from the blood cells was relatively prolonged. Extremely low radioactivity levels were found only in the brain. The ratio of brain-to-plasma levels was as low as 8% at the maximum.