NOVEL LIPOSOME VECTORS OF ACTIVE PRINCIPLES

摘要

The invention concerns liposome vectors, in powder form, of active principles, and more particularly active principles sensitive to digestive and/or plasmatic degradation, such as proteins, and their application as medicine. Said liposome vectors of active principles consist of a powder composition essentially constituted of unilamellar liposomes comprising an external lipid phase consisting of class 4 lipids (phospholipids), optionally associated with class 2 substances, class 3 substances and/or class 5 substances and an internal aqueous nucleus consisting of a mixture M of at least two different non-polymerisable gelling agents (G1 and G2) whereof the gel-sol phase transition is not less than 37 °C, G1 being selected among gelatines and carrageenans and G2 being selected among carrageenans with properties different from the carrageenans selected for G1, and celluloses, which liposomes have a diameter ranging between 20 nm and 1 mm, preferably between 20 nm and 500 nm; said composition having the form of particulate units with an average particle diameter between 10 mm and 1000 mm, formed by one or several of said liposomes, enclosed in a sheath selected in the group consisting of a dehydrated thermoreversible aqueous gel identical to said internal nucleus aqueous gel, dextrins or a mixture thereof, such that they contain, on an average, 10?16 to 1018¿ liposomes per gram of powder; and at least an active principle contained, as the case may be, either in the gelled internal nucleus or in the external lipid phase.