Patent EP0314764B1 successfully refreshed from Google Patents.
EP0314764B1
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Injectable opacifying liposome composition
Assignee: Dibra SpA
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Filing: 1988-05-16
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Granted: 1992-09-09
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Expires: 2008-05-16
Abstract
Abstract Injectable aqueous composition intended for opacifying certain organs with a view to examination by X-rays. This composition is based on liposomes containing, encapsulated thereein, an aqueous solution of an iodinated opacifying agent. The ratio between the weight of iodine encapsulated by the liposomes and the weight of the lipids from which their membrane is formed is not lower than 1.5 mg/mg.
Inventors
- 👤 Michel Schneider
- 👤 Hervé Tournier
- 👤 Bernard Lamy
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 18:27
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/04; A61K49/0433; A61K49/0447; A61K49/0461; A61K49/0466
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
95 words
I. Injectable aqueous composition, developed for opacifying organs for X-ray examination, formed of a suspension in a physically tolerable aqueous medium of liposomic vesicles having a lipidic membrane containing, encapsulated in these vesicles, at least one iodinated organic compound opaque to X-rays in aqueous solution, characterized in that the vesicles of the liposomes have a mean size which is between 0.15 and 3 f..lm, and that the ratio of the weight of the iodine encapsulated in the liposomic vesticles to the weight of the lipids of the said membrane in from 1.5 to 6 g/g.
Claim 2
Dependent Claim
26 words
Composition according to claim I, characterized in that the polydispersivity of the size of the vesicles in the range under consideration is not higher than 4.
Claim 3
Dependent Claim
35 words
Composition according to claim I, of which the concentration of lipids in suspension in the said aqueous medium is between 20 and 60 g/I, characterized in that its viscosity does not exceed 30mPa.s at 37°C.
Claim 4
Dependent Claim
96 words
Process for making the composition according to claim I by increasing the encapsulation capacity of an aqueous suspension of liposomes comprising lipidic membrane vesicles containing, in encapsulated form, at least one opacifying agent to X-rays in solution in an aqueous liquid, characterized in that these liposomes in suspension in the said aqueous liquid are subjected to an extrusion through a filtering membrane with porosities ranging between 0.4 and 3 mm, so as to "normalize" the size of the said vesicles in a range of values corresponding to the size of the pores of the said membrane.
Claim 5
Dependent Claim
23 words
Process according to claim 4, characterized in that, after normalisation by extrusion, the polydispersivity index of the vesicles is not higher than 4.
Claim 6
Dependent Claim
57 words
Process according to claim 4, characterized in that the suspension of "normalized" liposomes is subjected to an ultracentrifugation or to an ultrafiltration in order to separate or concentrate the said vesicles which are then redispersed in a new dispersion medium free from dissolved iodine, the effect of this operation being to reduce the proportion of non-encapsulated iodine.
Claim 7
Dependent Claim
26 words
Process according to claim 4, characterized in that, after normalisation, the size of at least 70% of the liposomic vesicles is between 0.2 and 2 µm.
Claim 8
Dependent Claim
54 words
Process according to claim 4, characterized in that the suspension of "normalized" liposomes is subjected to a microfiltration, the effect of this operation being to eliminate a residual quantity of liposomes of which the size is below the said range, and also to reduce the concentration of non-encapsulated iodine of the aqueous suspension agent.
Claim 9
Dependent Claim
41 words
Process according to claim 4, characterized in that the operation takes place at a temperature higher than the transition temperature of the lipids constituting the liposomic membrane, the result of these conditions being to increase the concentration of the encapsulated iodine.
Claim 10
Dependent Claim
14 words
Process according to claim 9, characterized in this temperature is between 50 and 90°C.
Claim 11
Dependent Claim
30 words
II. Composition according to claim I, characterized in that the iodinated organic compound is selected from iopamidol, iomeprol, iohexol, iopentol, iopromide, iosimide, ioversol, iotrolan, iotasul, iodixanol, iodecimol, 1,3- bis-(N-3,5-bis-(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodo-phenyl)- N-hydroxyacetyl-amino)-propane.
Claim 12
Dependent Claim
38 words
Composition according to claim I, characterized in that the lipids are selected from one or more of the hydrogenated soya lecithins, dipalmitoyl-phosphatidyl choline (DPPC), distearoyl-phosphatidyl choline (DSPC), sphingomyeline (SM), dicetyl-phosphate (DCP), diplamitoyl-phosphatidyl glycerol (DPPG) and dipalmitoyl-phosphatidic acid (DPPA).
References Cited (Backward Citations)
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