Dipalmitoylphosphatidylcholine liposomes with soybean-derived sterols and cholesterol as a carrier for the oral administration of insulin in rats.
Dipalmitoylphosphatidylcholine (DPPC) liposomes with a soybean-derived sterol mixture (SS) or cholesterol (Ch) were examined as a carrier for the oral administration of insulin in rats. Four kinds of liposomes were prepared: liposomes containing SS or Ch (molar ratio of DPPC/X = 7:2 or 7:4, X = SS or Ch), respectively. The pharmacological availability was greater and the lag time for the glucose reduction was later in the order of DPPC/SS (7:4) > DPPC/SS (7:2) > DPPC/Ch (7:4) > > DPPC/Ch (7:2)-liposomes. This order appears to correspond well with that of the rigidity of the liposomal membrane. In particular, DPPC/SS (7:4)-liposomes reduced blood glucose levels for up to 21 h in rats after oral administration. The highest absolute pharmacological availability was 31.6% at a dose of 20.0 IU/kg of DPPC/SS (7:4)-liposomes among the liposomes in comparison to intravenous administration.
Muramatsu
K
K
Department of Pharmaceutics, Hoshi University, Tokyo, Japan.
Maitani
Y
Y
Nagai
T
T
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000008:administration & dosage*; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D001786:Blood Glucose / Q000032:analysis; D002784:Cholesterol / Q000008:administration & dosage*; D004337:Drug Carriers; D007328:Insulin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008081:Liposomes; D008297:Male; D010840:Phytosterols / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D004337:Drug Carriers; D007328:Insulin; D008081:Liposomes; D010840:Phytosterols; D015060:1,2-Dipalmitoylphosphatidylcholine; D002784:Cholesterol