Novel oral formulation of paclitaxel inhibits neointimal hyperplasia in a rat carotid artery injury model.
BACKGROUND
Paclitaxel has been shown to inhibit vascular smooth muscle cell migration and proliferation contributing to neointimal formation. This study tested whether novel oral formulations of paclitaxel can prevent neointimal formation in a rat carotid artery injury model.


RESULTS
Oral formulations of paclitaxel (0, 5, 7.5, or 10 mg/kg) were administered to 40 rats by gavage for 5 days after injury. The peak plasma levels of paclitaxel administered at 5, 7.5, and 10 mg/kg were 61+/-16, 89+/-22, and 108+/-28 nmol/L, respectively. Treatment effects were assessed 11 days after injury. The angiographic minimum luminal diameters of the oral paclitaxel groups treated at 5, 7.5, and 10 mg/kg were 6.28+/-2.09, 6.97+/-1.79, and 7.97+/-1.57 AU, and these were significantly larger than that of the control group (4.67+/-1.45 AU). The oral paclitaxel groups (5, 7.5, 10 mg/kg; 0.05+/-0.05, 0.04+/-0.03, 0.05+/-0.03 mm2) showed significant neointimal formation reductions versus the control group (0.13+/-0.05 mm2). All rats survived to study completion. Only 2 animals in the 10 mg/kg group experienced weight loss ( approximately 10%) and loose stools between 4 and 6 days after injury. All other animals appeared healthy during the study. For comparison purposes, intraperitoneal formulations of paclitaxel (0 or 2 mg/kg) were administered by injection to 15 rats. We confirmed that the intraperitoneal administration of paclitaxel also effectively inhibited neointimal formation.


CONCLUSIONS
Oral formulations of paclitaxel provide an effective means of inhibiting proliferative response to vascular injury in the rat. Thus, oral formulations of paclitaxel may prevent human restenosis without significant toxicity.
Department of Internal Medicine, Chungbuk National University, Cheongju, Korea. kdwoon@chungbuk.ac.kr
Dong-Woon
DW
Kim
Jin-Sook
JS
Kwon
Young-Gyu
YG
Kim
Maeng Sup
MS
Kim
Gwan-Sun
GS
Lee
Tae-Jin
TJ
Youn
Myeong-Chan
MC
Cho
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D020212:Carotid Artery Injuries / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D016893:Carotid Stenosis / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D002404:Catheterization / Q000009:adverse effects; D002455:Cell Division; D005026:Ethylene Glycols / Q000008:administration & dosage; D005990:Glycerol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006965:Hyperplasia; D007263:Infusions, Parenteral; D007422:Intestines / Q000187:drug effects; D008041:Linoleic Acids / Q000008:administration & dosage; D008297:Male; D023421:Models, Animal; D032389:Myocytes, Smooth Muscle / Q000187:drug effects; D017239:Paclitaxel / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D014677:Pharmaceutical Vehicles; D011136:Polysorbates / Q000008:administration & dosage; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D012008:Recurrence; D013501:Surface-Active Agents / Q000008:administration & dosage; D024505:Tocopherols; D017539:Tunica Intima / Q000187:drug effects* / Q000473:pathology; D014700:Verapamil / Q000031:analogs & derivatives* / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000031:analogs & derivatives*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005026:Ethylene Glycols; C476929:KR30031; D008041:Linoleic Acids; D014677:Pharmaceutical Vehicles; D011136:Polysorbates; D013501:Surface-Active Agents; C000515:cremophor EL; C010111:carbitol; D014700:Verapamil; D024502:alpha-Tocopherol; C007678:ethyl linoleate; D017239:Paclitaxel; D005990:Glycerol; D024505:Tocopherols