Process for the preparation of a liposome dispersion under elevated pressure contents

A process for the preparation of a liposome dispersion comprising

• subjecting at least one phospholipid of the formula ##STR2## wherein R.sub.1 is C.sub.10-20 acyl,
• R.sub.2 is hydrogen or C.sub.10-20 acyl, and
• R.sub.3 is hydrogen, 2-trimethylamino-1-ethyl, 2-amino-1-ethyl, C.sub.1-4 alkyl, C.sub.1-5 alkyl substituted by carboxy, C.sub.2-5 alkyl substituted by hydroxy, C.sub.2-5 alkyl substituted by carboxy and by hydroxy, or C.sub.2-5 alkyl substituted by carboxy and by amino, or a salt of such phospholipid to a mobile carrier phase consisting of carbon dioxide and a polar organic solvent under pressure and temperature conditions which are higher than the critical pressure and the critical temperature of a pure carbon dioxide phase, reducing the compressed mixed phase that is obtainable to normal pressure and transferring it to an aqueous phase comprising water in the purity required for the intended application and a non-proteinaceous substance or a mixture of non-proteinaceous substances having water-soluble or hydrophilic properties for encapsulation in liposomes and removing the organic solvent and/or separating off a fraction of liposomes having a desired diameter range and/or converting the liposome dispersion into a form suitable for the intended application.