Oil-in-water emulsions for reconstituting lamellarity of the...

Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C424S455000, C514S938000, C252S391000

Reexamination Certificate

active

06379681

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to so-called lamellar emulsions of which the emulsion droplets are surrounded by a liquid-crystalline lamellar phase of lipid molecules and water and are thus particularly stabilized and which are particularly suitable for restoring the disturbed degree of order of damaged skin.
2. Discussion of Related Art
It is known from the technical literature that lamellar emulsions are capable of favorably influencing the water metabolism of the skin and of storing large amounts of moisture in the skin. According to G. Dahms, Cosmetics & Toiletries, Vol. 101, November 1986, pages 113-115, lamellar emulsions can be produced by using an oil with an emulsifier of similar structure. EP-A-0 641 557 recommends the use of a lipophilic surfactant, a hydrophilic surfactant and a free fatty acid as emulsifier components. According to WO 94/17830, sorbitan and sucrose fatty acid esters are used as emulsifiers while, according to WO 95/28913 A1, urea is additionally used for the production of lamellar emulsions.
It has now been found that it is not so much the nature of the oil or emulsifier as the choice of a suitable co-emulsifier which is crucial to the production of oil-in-water emulsions containing anisotropic lamellar phases.
DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to an oil-in-water emulsion with lamellar liquid crystalline phases containing a cosmetic oil or fatty component, a hydrophilic emulsifier and a lipophilic co-emulsifier, characterized in that the lipophilic co-emulsifier used is a lipid corresponding to the general formula R
1
—O—R
2
, where R
1
is a primary linear alkyl, alkenyl or acyl group containing 20 to 30 carbon atoms and R
2
is hydrogen, a group with the formula —(C
n
H
2n
O)
x
—H, where x=1 or 2 and n=2-4, or a polyhydroxyalkyl group containing 4 to 6 carbon atoms and 2 to 5 hydroxyl groups.
The oil-in-water emulsions according to the invention may contain either a cosmetic oil or fatty component or a water-in-oil emulsion as the inner phase. In the latter case, the lamellar emulsions according to the invention are water-in-oil-in-water emulsions.
The lipophilic co-emulsifier R
1
—O—R
2
is preferably a behenic or erucyl derivative, in which R
1
is a linear terminally substituted alkyl, alkenyl or acyl group containing 22 carbon atoms, in a quantity of 10 to 90% by weight of the oil phase. In a particularly preferred embodiment, behenyl alcohol is present as the lipophilic co-emulsifier in a quantity of 20 to 80% by weight, based on the oil phase as a whole.
Other suitable co-emulsifiers are products of the addition of 1 or 2 moles of ethylene oxide or propylene oxide onto behenyl alcohol, erucyl alcohol, arachidyl alcohol or even onto behenic acid or erucic acid. Finally, other suitable co-emulsifiers are the monoesters of C
20-30
fatty acids with polyols such as, for example, pentaerythritol, trimethylol propane, diglycerol, sorbitol, glucose or methyl glucose, Examples of such products are, for example, sorbitan monobehenate or pentaerythritol monoerucate.
Suitable hydrophilic emulsifiers for the production of the oil-in-water emulsions according to the invention are any surfactants suitable for the emulsification of cosmetic oil and fatty components. These are, above all, ionic emulsifiers or nonionic emulsifiers with an HLB value of 8 to 18. The HLB value is a value which can be calculated from the structure of the molecule in accordance with the equation HLB=0.2×(100 −L) where L is the percentage by weight of the lipophilic alkyl, alkenyl or acyl groups in the molecule.
Suitable ionic emulsifiers are anionic, cationic, zwitterionic and amphoteric surfactants, preferably those containing a primary linear C
12-18
alkyl or alkenyl group. Suitable anionic emulsifiers are, for example, the salts of C
12-18
fatty acids, of sulfuric acid monoesters or phosphoric acid monoesters of C
12-18
fatty alcohols, of C
12-18
acyl isethionic acids, of C
12-18
alkane sulfonic acids or of C
12-18
acylamino acids. Cationic emulsifiers are, for example, cetyl trimethyl ammonium chloride or dimethoxyethyl hydroxyethyl methyl ammonium chloride. Suitable zwitterionic surfactants are, for example, betaine surfactants, such as stearamidopropyl dimethyl carboxymethyl ammonium betaine, while suitable amphoteric surfactants are, for example, cetyl aminopropionic acid or cocoamphocarboxyglycinate. Amine oxide surfactants are also suitable hydrophilic emulsifiers.
Suitable nonionic surfactants with HLB values of 8 to 18 are, in particular, products of the addition of ethylene oxide onto fatty acids, fatty alcohols, fatty acid alkanolamides, fatty acid monoglycerides, sorbitan fatty acid esters, methyl glucoside fatty acid esters or other lipids containing carboxyl, hydroxyl or amino groups; the percentage content of ethoxy groups formed should be at least 40% by weight. Other suitable nonionic surfactants are alkyl polyglucosides, sugar esters and polyglycerol fatty acid esters.
Suitable oil and fatty components are any vegetable, animal, mineral and synthetic oils, fats and waxes suitable for use on the human body for physiological and aesthetic reasons. Examples include paraffins, fatty acid esters of monohydric or polyhydric alcohols, for example triglycerides, fatty acid/fatty alcohol esters, fatty acid/dicarboxylic acid/polyol polyesters, fatty alcohol/diol/dicarboxylic acid polyesters, di-n-alkyl ethers, polyolefins or silicone oils. Liquid oils or mixtures of oils and waxes which are liquid at 20° C. are preferably used. Monoesters suitable as oil components are, for example, the methyl esters and isopropyl esters of fatty acids containing 12 to 22 carbon atoms such as, for example, methyl laurate, methyl stearate, methyl oleate, methyl erucate, isopropyl palmitate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, isopropyl oleate. Other suitable monoesters are, for example, n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, isononyl palmitate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-hexyidecyl stearate, 2-octyldodecyl palmitate, oleyl oleate, oleyl erucate, erucyl oleate and esters obtainable from technical aliphatic alcohols mixture. and technical aliphatic carboxylic acids, for example esters of saturated and unsaturated fatty alcohols containing 12 to 22 carbon atoms and saturated and unsaturated fatty acids containing 12 to 22 carbon atoms which are obtainable from animal and vegetable fats. Naturally occurring monoester or wax ester mixtures, as present for example in jojoba oil or in sperm oil, are also suitable.
Suitable dicarboxylic acid esters are, for example, di-n-butyl adipate, di-n-butyl sebacate, di-(2-ethylhexyl)-adipate, di-(2-hexyldecyl)-succinate and diisotridecyl azelate. Suitable diol esters (III) are, for example, ethylene glycol dioleate, ethylene glycol diisotridecanoate, propylene glycol di-(2-ethylhexanoate), butanediol diisostearate and neopentyl glycol dicaprylate.
Suitable fatty acid triglycerides are natural vegetable oils, for example olive oil, sunflower oil, soybean oil, peanut oil, rapeseed oil, almond oil, palm oil and even the liquid fractions of coconut oil or palm oil, and animal oils such as, for example, neat's foot oil, the liquid fractions of beef tallow or even synthetic triglycerides of the type obtained by esterifying glycerol with C
8-22
fatty acids, for example triglycerides of caprylic acid/capric acid mixtures, triglycerides of technical oleic acid or palmitic acid mixtures.
The oil-in-water emulsions of cosmetic oil or fatty components containing lamellar liquid crystalline phases according to the invention are produced by methods known per se using hydrophilic emulsifiers and lipophilic co-emulsifiers, the aqueous phase which may contain hydrophilic emulsifiers being intensively mixed with the oil or fatty phase which contains as lipophilic co-emulsifiers at least one lipid corresponding to the general formula R
1
—O—R
2

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Oil-in-water emulsions for reconstituting lamellarity of the... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Oil-in-water emulsions for reconstituting lamellarity of the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oil-in-water emulsions for reconstituting lamellarity of the... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2830694

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.