Transparent oil-in-water emulsion
The present invention relates to transparent or clear emulsions for cosmetic or pharmaceutical use. The transparent emulsions of the present invention comprise an oil phase, containing at least one lipophilic solvent; an aqueous phase; and an emulsifying system containing at least one non-ethoxylated fatty acid ester emulsifier having a hydrophilic-lipophilic balance (“HLB”) from about 11 to about 16. Preferred non-ethoxylated fatty acid ester emulsifiers are sucrose esters, in particular sucrose palmitate and sucrose laurate.
1. A transparent oil-in-water gel emulsion composition for application to skin or hair comprising:
(a) an oil phase, containing at least one lipophilic solvent;
(b) an aqueous phase, containing at least one polyol;
(c) at least one sucrose ester emulsifier having an HLB from about 11 to about 16 at a concentration of less than 5% by weight of the total composition; wherein the at least one sucrose ester emulsifier is selected from the group consisting of sucrose laurate, sucrose stearate, sucrose palmitate, sucrose oleate, sucrose myristate, sucrose cocoate, and sucrose isostearate; and
(d) a polymeric thickener wherein the polymeric thickener is selected from the group consisting of sclerotium gum, xanthan gum, sodium alginate, Carbomer, cellulose ethers, steareth-20 methylacrylate copolymer and C10-C30 alkyl acrylate crosspolymer
wherein the refractive index of the aqueous phase is about or less than +/−0.005 of that of the oil phase.
2. A composition according to claim 1 wherein the lipophilic solvent of the oil phase is selected from the group consisting of volatile silicone fluids, non-volatile silicone fluids, high molecular weight silicone polymers in the viscosity range of from about 60,000 centistokes to about 1,000,000 centistokes, liquid fatty alcohols from 16 to 22 carbon atoms per molecule, volatile hydrocarbon fluids, esters and vegetable oils.
3. A composition according to claim 2 wherein the lipophilic solvent of the oil phase is a volatile silicone fluid.
4. A composition according to claim 3 wherein the volatile silicone fluid is selected from the group consisting of cyclomethicone (cyclopentasiloxane, cyclohexasiloxane, cyclotetrasiloxane) and dimethicone (0.65 centistokes).
5. A composition according to claim 2 wherein the lipophilic solvent of the oil phase is a volatile hydrocarbon fluid.
6. A composition according to claim 5 wherein the volatile hydrocarbon fluid is isododecane.
7. A composition according to claim 1 wherein the lipophilic solvent of the oil phase further comprises a lipophilic co-solvent selected from the group consisting of fatty acid esters and triglycerides.
8. A composition according to claim 1 wherein the polyol of the aqueous phase is selected from the group consisting of glycerin, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3 butylene glycol, methylpropanediol, hexylene glycol and sorbitol.
9. A composition according to claim 1 wherein the molecular weight of the polyol is from about 300 to about 1,000 daltons.
10. A composition according to claim 1 wherein the polyol is polyethylene glycol 400.
11. A composition according to claim 1 wherein the at least one sucrose ester emulsifier is present at a concentration of less than about 3% by weight of the total composition.
12. A composition according to claim 11 wherein the at least one sucrose ester is a sucrose laurate.
13. A composition according to claim 11 wherein the at least one sucrose ester is a sucrose palmitate.
14. composition according to claim 1 wherein the at least one sucrose ester emulsifier is present at a concentration of less than about 1.5% by weight of the total composition.
15. A composition according to claim 14 wherein the at least one sucrose ester is a sucrose laurate.
16. A composition according to claim 14 wherein the at least one sucrose ester is a sucrose palmitate.