Pharmacokinetics of tiqueside (beta-tigogenin cellobioside) in dogs, rats, rabbits, and monkeys.
Tiqueside (CP-88,818, beta-tigogenin cellobioside) is an effective cholesterol absorption inhibitor that may be useful in the treatment of hypercholesteremia. We have investigated the pharmacokinetics of tiqueside in dogs, rats, rabbits, and monkeys. In dogs, the volume of distribution (Vdss) was 2.11 L/kg, clearance was 0.58 mL/min-kg, and half-life was 45 h following a 1.4 mg/kg intravenous dose. Absolute bioavailability in fed dogs decreased from 6.7% for a 30 mg/kg dose to 1.7% for a 375 mg/kg dose. The oral bioavailability at a dose of 375 mg/kg was approximately 4-fold lower in fasted dogs than fed dogs. AUC-(0-24) for doses up to 2000 mg/kg were only slightly greater than AUC-(0-24) for a 375 mg/kg dose. In rats dosed intravenously at 8.0 mg/kg, Vdss was 3.52 L/kg, clearance was 14.6 mL/min-kg, and half-life was 3.6 h. Estimated bioavailability for rats dosed in feed at 250-2000 mg/kg/day was less than 0.5%. In rabbits dosed at 4.0 mg/kg i.v., Vdss was 2.95 L/kg, clearance was 0.59 mL/min-kg, and half-life was 61 h. Bioavailability for rabbits dosed in feed at 62.5 or 125 mg/kg/day was approximately 7%. Systemic exposure in rhesus monkeys after oral dosing was lower than that for dogs and rabbits. Thus, low systemic exposure to tiqueside following oral administration has been demonstrated in several animal species.
Inskeep
P B
PB
Drug Metabolism Department, Pfizer Inc, Groton, CT 06340.
Connolly
A G
AG
Cole
M J
MJ
Luther
E W
EW
Biehl
M L
ML
Marzetta
C A
CA
Savoy
Y E
YE
Silber
B M
BM
D000818:Animals; D000924:Anticholesteremic Agents / Q000493:pharmacokinetics*; D001682:Biological Availability; D004285:Dogs; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous; D008253:Macaca mulatta; D008297:Male; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000493:pharmacokinetics*; D013045:Species Specificity
D000924:Anticholesteremic Agents; D012503:Saponins; C080606:tiqueside