Guy Vanlerberghe

The effect of non‐ionic surfactant vesicle (niosome) entrapment on the absorption and distribution of methotrexate in mice

Non‐ionic surfactant vesicles (niosomes) prepared from a non‐ionic surfactant, cholesterol and dicetyl phosphate and containing methotrexate (MTX) have been administered to mice. Given intravenously the niosomes prolong the levels of MTX in the blood, large amounts of the drug being taken up by the liver. There was also an increased uptake of MTX into the brain, perhaps due to an effect of the niosome components on the permeability of the blood brain barrier. Absorption of the drug from the gastrointestinal tract following oral ingestion, appeared to be increased at some doses; most of the entrapped MTX was taken up by the liver, but uptake of MTX into the brain was also increased. The metabolic profile of the drug is altered by the niosomes which appear to prevent the rapid formation of 7‐hydroxy methotrexate.

Polyhedral non-ionic surfactant vesicles

Large polyhedral (2–10 μm) non‐ionic surfactant vesicles (niosomes) formed from mixtures of a hexadecyl diglycerol ether (C16G2), a cholesteryl poly‐24‐oxyethylene ether (solulan C24) and a low level of cholesterol are being investigated as slow‐release systems for ophthalmic, subcutaneous or intramuscular administration.