B. Mccormack et G. Gregoriadis, ENTRAPMENT OF CYCLODEXTRIN DRUG COMPLEXES INTO LIPOSOMES - POTENTIAL ADVANTAGES IN DRUG-DELIVERY, Journal of drug targeting., 2(5), 1994, pp. 449-454
A novel concept in drug delivery discussed here, takes advantage of ce
rtain properties of the drug ''containers'' cyclodextrins and liposome
s to combine them into a single system thus circumventing problems ass
ociated with both systems. The concept, entailing entrapment of water-
soluble cyclodextrin-drug inclusion complexes in liposomes, would allo
w accommodation of insoluble drugs in the aqueous phase of vesicles. T
his would potentially increase the drug to lipid mass ratio to levels
above those attained by conventional drug incorporation into the lipid
phase, enlarge the range of insoluble drugs amenable to encapsulation
to include, for instance, membrane destabilizing agents, allow target
ing of complexes to specific sites and reduce toxicity. In the present
work, soluble inclusion complexes of hydroxypropyl-beta-cyclodextrin
with dehydroepiandrosterone, retinol and retinoic acid were prepared a
nd entrapped into mutlilamellar liposomes by the dehydration-rehydrati
on procedure. Complex-containing liposomes were then exposed to blood
plasma. Results show that complex entrapment into liposomes depends on
the lipid composition used. Nearly all of the cyclodextrin and consid
erable portions of the drugs were found to remain associated with the
carrier in the presence of plasma.