Claims
- 1. A process for imparting hydrolysis stability to vesicles dispersed in an aqueous phase, said vesicles comprising a membrane of a lipid phase encapsulating an aqueous phase, said vesicles being prepared from a lipid phase, said process comprising combining a nonionic amphiphilic lipid mixture with at least one ionic amphiphilic lipid in an amount sufficient to impart to said aqueous phase a pH ranging from 5.5 to 7.5
- said nonionic amphiphilic lipid mixture being a mixture of esters of at least one polyol and a fatty acid, said at least one polyol being selected from the group consisting of polyethylene glycol containing 1 to 60 ethylene oxide units, sorbitan, sorbitan containing 2 to 60 ethylene oxide units, glycerol containing 2 to 30 ethylene oxide units, a polyglycerol containing 2 to 15 glycerol units, sucrose, and glucose containing 2 to 30 ethylene oxide units, and said fatty acid being a fatty acid containing a saturated or unsaturated, linear or branched C.sub.5 -C.sub.17 alkyl chain, the number of alkyl chains per polyol group ranging from 1 to 10; and
- said ionic amphiphilic lipid being selected from the group consisting of an alkali metal salt of dicetyl phosphate, an alkali metal salt of dimyristyl phosphate, and alkali metal salt of cholesterol sulphate, an alkali metal salt of cholesterol phosphate, monosodium acyl glutamate, disodium acyglutamate, a phospholipid and an alkyl sulphonic compound having the formula: ##STR7## wherein R represents C.sub.16 H.sub.33 or C.sub.18 H.sub.37 and M represents an alkali metal, or a mixture thereof;
- the weight ratio of said nonionic amphiphilic lipid to said ionic amphiphilic lipid in said lipid phase being between 50:1 and 50:25.
- 2. The process of claim 1 wherein said membrane of a lipid phase of said vesicles contains at least one additive selected from the group consisting of a sterol, a long chain alcohol, a long chain diol and a long chain amine.
- 3. The process of claim 2 wherein said sterol is cholesterol.
- 4. The process of claim 1 wherein said vesicles contain at least one active agent having cosmetic or dermopharmaceutic activity, or both.
- 5. The process of claim 4 wherein said active agent is a water-soluble active agent which is present in said aqueous phase encapsulated in said vesicles.
- 6. The process of claim 4 wherein said active agent is a fat-soluble active agent and is present in said lipid phase constituting said membrane of said vesicles.
- 7. The process of claim 6 wherein said fat-soluble active agent is selected from the group consisting of a spingomyeline, a glycoceramide, a natural ceramide and a synthetic ceramide.
- 8. The process of claim 1 wherein said membrane of a lipid phase of said vesicles contains a mixture of cholesterol and a natural or synthetic ceramide.
- 9. The process of claim 4 wherein said vesicles contain an amphiphilic active agent distributed between said lipid phase and said aqueous phase encapsulated in said vesicles.
- 10. The process of claim 1 wherein said aqueous dispersion phase also contains at least one adjuvant selected from the group consisting of a gelling agent, a preservative, a colorant, a pigment, a filler, an opacifier and a perfume.
- 11. The process of claim 10 wherein said pigment is coated with a silicone, a fluorinated compound selected from the group consisting of a perfluoroalkyl phosphate and a polytetrafluoroethylene or an amino acid.
- 12. The process of claim 10 wherein said pigment is an iron oxide or a titanium oxide.
- 13. The process of claim 10 wherein said filler is selected from the group consisting of talc, mica, starch powder, nylon powder and silica powder.
Priority Claims (2)
Number |
Date |
Country |
Kind |
92 09603 |
Aug 1992 |
FRX |
|
92 12343 |
Oct 1992 |
FRX |
|
Parent Case Info
This is a continuation of application Ser. No. 08/473,360, filed Jun. 7, 1995 abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0319638 |
Jun 1989 |
EPX |
0433131 |
Jun 1991 |
EPX |
2552666 |
Apr 1985 |
FRX |
2151203 |
Jul 1985 |
GBX |
9006747 |
Jun 1990 |
WOX |
Non-Patent Literature Citations (2)
Entry |
French Search Report--FR 92 09603. |
French Search Report--FR 92 12343. |
Continuations (1)
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Number |
Date |
Country |
Parent |
473360 |
Jun 1995 |
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