WO2003020318A1

WO2003020318A1 - A topical w/o-emulsion composition

Info

Publication number: WO2003020318A1
Application number: PCT/SE2002/001571
Authority: WO
Inventors: Andreas Fischer
Original assignee: LIPOCORE HOLDING AB
Current assignee: LIPOCORE HOLDING AB
Priority date: 2001-09-04
Filing date: 2002-09-03
Publication date: 2003-03-13
Anticipated expiration: 2004-03-04

Abstract

The present invention refers to a topical w/o-emulsion composition for cosmetic or medical use, comprising an oil phase and an aqueous phase dispersed in the continuous oil phase. The oil phase contains at least one non-polar oil, monoglycosyl-ceramide, and optionally ethanol. The composition is able to form a macroscopically homogeneous and stable w/o-emulsion.

Description

A TOPICAL W/O-EMULSION COMPOSITION

TECHNICAL FIELD

The present invention is related to a new topical w/o- emulsion composition for cosmetic or medical use.

BACKGROUND OF THE INVENTION

There are today many chemicals overflowing the market for cosmetic compositions. A typical cosmetic composition, e.g. a skin cream, often contains up to twenty different ingredients, many of whic are of synthetic origin, with no analogues in natural occurring structures . This has created an intricate problem where the use of cosmetics, as a means to improve skin deficiencies, may at the same time create new problems, as a side effect of exposing the body to unsuitable solvents and unnatural ingredients .

There is also an interest within the cosmetic industry to produce w/o-emulsions without a greasy feeling, which often is a problem with said emulsions. Further, there is an increasing trend within the cosmetic and pharmaceutical industry to incorporate different additives, such as cosmetic ingredients and bioactive substances, into topical compositions.

PRIOR ART

WO 01/66086, in the name of Lipocore Holding AB, refers to a lipid carrier for controlled release of a bioactive substance, the structure of which is retained in an aqueous environment . The carrier composition comprises a triglyceride oil, a polar lipid selected from the group of phosphatidyl- ethanolamine and monohexosylceramide, and ethanol. The carrier consists entirely of a lipid, or oil, phase, and is therefore well suited for incorporating lipophilic substances; the carrier is, however, incapable of dissolving lipophobic, hydrophilic substances . US 5,912,271, in the name of Astra AB, refers to a composition comprising one or more local anaesthetic agents, one or more polar lipids, a triacylglycerol and optionally water. When sphingolipid materials are used the preferred sphingolipid is sphingomyelin, or products derived from sphingomyelin. In all examples containing sphingolipid materials the sphingomyelin content of the materials lies between 60 and 98 %.

JP2000-119178A, in the name of Shionogi & Co., Ltd., refers to a composition comprising a ceramide, monohydric lower alcohol, oil and water, which composition is capable of forming a transparent solution in an equilibrium state, i.e. not an emulsion. The disclosed ceramides can all be dissolved in the composition without heating. Preferred ceramides are ceramide 1, ceramide 3 and ceramide 6 obtained from Cosmoferm B.V., Delft, The Netherlands. Said ceramides do not have a glycosyl moiety attached to the sphingoid group, that is they are not glycosylceramides .

OBJECTIVES OF THE INVENTION It is an objective of the present invention to provide an improved topical composition with few and preferably natural constituents .

It is another objective of the present invention to provide a topical w/o-emulsion with a refreshing and pleasant feeling, free from greasiness .

It is yet another objective to provide a robust topical composition capable of incorporating cosmetic ingredients and bioactive substances .

DESCRIPTION OF THE INVENTION

It has now surprisingly been found that a w/o-emulsion of the composition stated below has excellent properties for topical administration, with a refreshing and pleasant feeling free from greasiness, and the ability to incorporate cosmetic ingredients or bioactive substances, or materials. The essential constituents of the w/o-emulsion of the present invention are based on components, which are either normal components of the human cells and membranes, or present in significant amounts in the human diet. This means that said constituents are biocompatible with human tissues and are metabolised in the same way as the corresponding endogenous lipids.

The present invention refers to a topical w/o-emulsion composition consisting of a w/o-emulsion comprising an oil phase and an aqueous phase dispersed in the continuous oil phase, wherein the oil phase contains at least one non-polar oil and a polar lipid material as emulsifier, characterised in that the polar lipid material is one or more monoglycosylceramides . The invention also refers to a topical w/o-emulsion composition comprising an oil phase and an aqueous phase dispersed in the continuous oil phase, wherein the oil phase contains at least one non-polar oil, a polar lipid material as emulsifier, and ethanol, characterised in that the polar lipid material is one or more monoglycosylceramides . The compositions of the invention are characterised by the essential emulsifying effect of the monoglycosylceramides, forming a macroscopically homogeneous and stable w/o-emulsion, with excellent topical properties .

Aqueous phase refers to any aqueous solution or dispersion with water as a solvent or dispersing medium. In the w/o-emulsion composition, the aqueous phase is dispersed as microscopic aqueous droplets in the continuous oil phase.

The non-polar oil can be a triglyceride oil, a mineral oil or a mixture thereof. A suitable oil is preferably a triglyceride oil, or in other words triacylglycerol oil, wherein the acyl groups are derived from unsaturated or saturated fatty acids or hydroxy fatty acids having 8-22 carbon atoms. In the w/o-emulsion composition of the invention the triglyceride oil can be selected from the group of natural vegetable oils consisting of, but not limited to, almond oil, coconut oil, maize oil, wheat germ oil, soybean oil, sesame oil, palm oil, safflower oil, evening primrose oil, sunflower oil, rape seed oil, linseed oil, corn oil, cottonseed oil, peanut oil, olive oil, or from the group of fractionated oils consisting of, but not limited ^"to, refined vegetable oils, and medium chain triglyceride oil (also called fractionated coconut oil) , or from the group of semi-synthetic oils consisting of, but not limited to, acetylated monoglyceride oils, or from the group of animal oils, consisting of, but not limited to, butter oil, marine oil, such as fish oil. Mineral oils can be exemplified by, but not limited to, hydrocarbon oil, liquid paraffin. Any mixture of said oils derived from any of the mentioned groups can also be used. Preferably the triglyceride oil is selected from the group consisting of medium chain triglyceride oil, sesame oil, evening primrose oil, sunflower oil, coconut oil, soybean oil, corn oil, fish oil, or a mixture thereof .

Monoglycosylceramides are monosaccharide-containing derivatives of ceramides. Ceramides are N-acylated sphingoids. A sphingoid is a long-chain aliphatic amino alcohol. A mono- glycosylceramide can be represented by the general formula I

I wherein R' and R" represent optionally substituted hydrocarbon chains .

The basic chemical structure of a sphingoid is represented by the compound originally called dihydrosphingosine, now referred to as sphinganine, or more specifically 2-amino-l,3- octadecanediol. There are many sphinganine homologues, which can differ in chain-length, degree of unsaturation and presence of substituents, such as hydroxyl, oxo, methyl, etc. Examples of sphinganine homologues, or sphingoids, are: 4-sphingenine (sphingosine) , icosasphinganine (C20-dihydrosphingosine) , 4- hydroxysphinganine (phytosphingosine) , 4-hydroxyicosaspnιnganme (C20-phytosphingosine) , 4-hydroxy-8-sphingenine (dehydrophyto- sphingosine) , 4, 8-sphingadienine (sphingadienine) , 4-hexadeca- sphingenine (C16-sphingosine) , hexadecasphinganine (C16- dihydrosphingosine) and heptadecasphingenine (C17-sphingosine) . The acyl chain linked to the amide nitrogen of naturally occurring ceramides can have a chain length from about 10 to 28 carbon atoms, more often from 16 to 26, and may contain one or more double bonds, and may contain one or more substituents, such as hydroxyl, oxo and lower alkyl, such as methyl. Obviously, synthetically produced ceramides can have much more diverse acyl chains linked to the amide nitrogen, in terms of chain length, double bonds, substituents, etc.

The invention especially refers to a carrier composition wherein the acyl chain linked to the amide nitrogen of the monoglycosylceramides is derived from unsaturated or saturated fatty acids having 10-28 carbon atoms (that is R" having 9-27 carbon atoms) .

According to another aspect of the invention the compo- sition contains monoglycosylceramides wherein the sphingoid base has 6-28 carbon atoms (that is R' has 3-25 carbon atoms) .

Preferred monoglycosylceramides according to the invention are monohexosylceramides, CMH, and in particular monogluco- sylceramide or monogalactosylceramide . Monohexosylceramide can be described by the following formula II

II wherein R^{^} and R" are de ined as in formula I .

Monohexosylceramides, CMH, also sometimes called cerebrosides, can be of synthetic or semi-synthetic origin, or obtained from milk or other dairy products, or from animal organs or materials, such as brain, spleen, liver, kiαney, erythrocytes, or from plant sources.

In monohexosylceramide from bovine milk the most commonly occurring sphingoid is sphingenine. Formula III below refers to a monoglucosylceramide based on sphingenine

III wherein R¹ and R² represent optionally substituted hydrocarbon chains .

Examples of other sphingoids present are hexadeca- sphingenine, hexadecasphinganine, heptadecasphingenine and sphinganine . In monohexosylceramide from bovine milk the acyl chains linked to the amide nitrogen of the ceramides range in chain length from about 12-28 carbon atoms, where the four most common acyl chains, C16:0, C22:0, C23:0 and C24:0, account for about 80 % by weight, as determined by gas chromatography. The average acyl chain length is about 22 carbon atoms and the fraction of unsaturated acyl chains is about 5 % by weight, as determined by gas chromatography.

According to a preferred aspect of the present invention the composition contains monohexosylceramides obtainable from bovine mil . An advantage of the monoglycosylceramides over phospho- lipids and many other polar lipids is the relatively high chemical stability due to a less tendency of oxidation and hydrolysis .

The topical characteristics of the composition of the present invention are depending on the composition of the oil phase, the composition of the aqueous phase and the ratio aqueous phase/oil phase, and can be controlled by selecting the proportions of the oil phase components and the aqueous phase components, and selecting the ratio aqueous phase/oil phase (the w/o ratio) . Said proportions can also be selected to optimise the incorporation of specific cosmetic ingredients or bioactive substances .

According to a preferred aspect, the composition of the invention consists of an oil phase of 60-99.9% by weight of at least one non-polar oil in combination with 0.1-40 % by weight of monoglycosylceramide, and an aqueous phase, in a w/o ratio of up to 80/20 by weight.

Another preferred topical composition, which includes ethanol, consists of an oil phase of 30-99.9 % by weight of at least one non-polar oil in combination with 0.1-40 % by weight of monoglycosylceramide, and up to 30 % by weight of ethanol, and an aqueous phase, in a w/o ratio of up to 80/20 by weight. Ethanol is not essential for obtaining a w/o-emulsion, but the presence of ethanol facilitates the preparation of the oil phase and the w/o-emulsion, and may be crucial for the incorporation of various additives .

The upper limit of the content of monoglycosylceramide is restrained by the possibility of achieving a homogeneous oil phase during the preparation of the w/o emulsion and by the high viscosity obtained in the oil phase at too high contents thereof. If the oil phase has a high viscosity, it is difficult to disperse the aqueous phase in the oil phase. To facilitate the preparation of a composition with a high content of monoglycosylceramides, that is to achieve a homogeneous oil phase and to reduce the viscosity of the oil phase, the content of ethanol can be varied. A high content of ethanol will facilitate the achievement of a homogeneous oil phase and lower the viscosity of both the oil phase and the w/o-emulsion composition. The upper limit of the w/o ratio is restrained by the possibility of achieving a homogeneous w/o-emulsion. At too high w/o ratios the oil phase cannot disperse the entire aqueous phase. The maximum w/o ratio differs with the composition of the oil phase and the aqueous phase. Depending on the special features wanted of the w/o- emulsion composition, the content of monoglycosylceramide, as well as the w/o ratio, may be adjusted. The characteristics ot the w/o-emulsion composition are also depending on the choice of non-polar oil, the content of ethanol and the presence of possible additives. According to a preferred aspect, the present invention refers to a topical composition wherein the content of monoglycosylceramide is 0.1-20 % by weight of the oil phase composition, preferably 0.2-10 %.

The composition of the invention can also contain one or more additives. Additives can be a cosmetic ingredient or a bioactive substance or an excipient .

Excipient can be defined as any component, other than the cosmetic ingredient or the bioactive substance, included in the topical composition. Excipients can be incorporated for the purpose of modifying physical or chemical properties of the composition, or as inert bulk, or volume, materials. The excipient can contribute to such properties of the composition as stability, solubility, polarity, viscosity, release properties, appearance, patient acceptability, and ease of production. Exci- pients are for instance antimicrobial preservatives, antioxi- dants, stabilisers, emulsifiers, complexing agents, thickeners and penetration enhancers.

As examples of excipients can be mentioned glycerol, ethylene glycol, polyethylene glycols, propylene glycol, poly- propylene glycols, fatty alcohols, sterols, such as cholesterol, monoglycerides, diglycerides, tetraglycol, propylene carbonate and copolymers of polyethylene oxide and polypropylene oxide, or a mixture thereof .

The w/o-emulsion composition of the present invention is suitable for incorporating cosmetic ingredients or bioactive substances, and thereby acts as a carrier for topical administration of such ingredients or substances. The composition can also be used as such, without any cosmetic or pharmaceutical materials. The composition displays excellent properties for topical use, as both monoglycosylceramides and non-polar oils, e.g. triglyceride oils or mineral oils, are believed to ne beneficial for the skin.

Although perfumes may be included to give the composition an appealing fragrance, this will not be necessary for masking any unpleasant odour. The monoglycosylceramides do not smell, as opposed to many of the more commonly used phospholipid materials .

The topical w/o-emulsion of the present invention is prepared in a relatively easy manner with few constituents, compared to other common topical compositions and compared to other w/o-emulsions. A mixture of monoglycosylceramide, a non- polar oil, and optionally ethanol is stirred in a sealed vial at an elevated temperature, typically 80 °C, until a homogeneous oil phase has been obtained, normally for 10 minutes. After the heating the oil phase is allowed to cool whereupon a macroscopically homogeneous, turbid oil phase of semi-solid consistency is formed. The aqueous phase is then added to the oil phase, and dispersed into the oil phase simply by supplying mechanical energy at a temperature from 0 °C to about 60 °C. A macroscopically homogeneous w/o-emulsion, often of a cream- or lotion-like consistency, is then obtained. Energy can be provided by vigorous mechanical or magnetic stirring, vortexing, shaking or by other means of agitation. Noteworthy is that the aqueous phase does not have to be heated during the preparation, which is a substantial advantage when thermally labile substances, or materials, are to be incorporated into the aqueous phase. Another advantage in the preparation of the w/o-emulsion of the present invention is that no organic solvents, apart from optionally ethanol, is used during the preparation. The common feature of the different topical compositions of the present invention is the specific emulsifying properties of the monoglycosylceramides.

W/o-emulsions are of a general interest to the cosmetic industry. The invention also refers to a cosmetic formulation for topical administration comprising a composition as previously described in combination with one or more cosmetic ingredients.

The cosmetic ingredient can be defined as a material, or substance, which is beneficial to the cosmetic properties of the composition, for example salts, lipids, vitamins, antioxidants, plant extracts, pH regulators, insect repellents, UV absorbers, a ino acids, chelating agents, moisturising agents, colouring agents and perfumes, to mention a few. The cosmetic ingredient is intended to be administered to various external parts of the human or animal body, such as epidermis, hair systems, nails, lips and external genital organs, or to the mucous membranes of the oral cavity, with the view of cleaning, perfuming, colouring or protecting them, or keeping them in good conditions, or changing their appearance . The invention also refers to a pharmaceutical formulation for topical administration comprising a w/o-emulsion composition as previously described in combination with a bioactive substance in a pharmaceutically effective amount .

The pharmaceutical formulation can for example be used for ocular, dental or dermal administration.

The bioactive substance can be defined as a biologically active substance, or material, which can be used within human or veterinary medicine for diagnosis, treatment or prevention of disease, or to affect the structure or function of the human or animal body. The invention especially refers to a pharmaceutical formulation wherein the bioactive substance is selected from the group consisting of antibiotic, antimicrobial, antiviral, anti- inflammatory, antifungal, antipsoriatic, antiseborrheic and antitumour drugs, anesthetics, insecticides, antiacne agents, hair growth stimulants, lipids, steroids, hormones, proteins, peptides, amino acids, minerals and vitamins.

A pharmaceutical formulation can comprise more than one bioactive substance.

The invention especially refers to a topical composition or formulation, which is a cream, an ointment or a lotion. The ability of the topical composition or formulation or the present invention to form macroscopically homogeneous w/o- emulsions of cream- or lotion-like consistency, even when the aqueous phase has a considerably high ionic strength or has a very acidic or basic pH value, see Example 30-33, demonstrates the high emulsifying effect of monoglycosylceramide and the robustness of the w/o-emulsion composition. Further, it implies that the w/o-emulsion is suitable for incorporating salts and other highly ionic substances in high amounts, and also for incorporating cosmetic ingredients or bioactive substances, requiring extreme pH values to dissolve or to retain stable, see Test of stability of the formulation of Example 17. Further, in the dispersed aqueous phase, which can be degassed, the composition can provide an aqueous environment with low oxygen content, which moreover is shielded from atmospheric oxygen. This makes the composition suitable for incorporating materials or substances that are easily oxidised or by other means degraded by the presence of oxygen in aqueous environments .

EXAMPLES OF COMPOSITIONS

Examples of compositions with different non-polar oils

Several different oils were tested in the composition. The relative proportions of the oil phase components (RP oil phase) and the ratio aqueous phase/oil phase (w/o) were tried to be kept to monoglycosylceramide/oil/ethanol : 5/85/10 %w/w, and aqueous phase/oil phase : 40/60 %w/w in all examples. The procedure for preparing the different compositions was the same in all examples. Monoglycosylceramide, oil and ethanol were mixed in a sealed 10 ml glass vial and stirred at 80 °C for 10 minutes to form a homogeneous oil phase . When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature, the aqueous phase was weighed into the glass vial . The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial. The resulting emulsion was m an examples, except Example 7 Castor oil, a macroscopically homogeneous w/o-emulsion of cream-like consistency.

Materials

Monohexosylceramide (CMH) was prepared from whey concentrate by means of chromatographic fractionation to a purity of >99% from Lipid Technologies Provider AB, Sweden. The non-polar oils were: MCT oil (medium chain triglyceride oil) from Croda

Oleochemicals, England;

Evening primrose oil (chromatographic fractionated) from Scotia

LipidTeknik AB, Sweden;

Sunflower oil (chromatographic fractionated) from Scotia LipidTeknik AB, Sweden;

Coconut oil (chromatographic fractionated) from Scotia

LipidTeknik AB, Sweden;

Soybean oil (chromatographic fractionated) from Scotia

LipidTeknik AB, Sweden; Corn oil (chromatographic fractionated) from Scotia LipidTeknik

AB, Sweden;

Castor oil from Apoteksbolaget AB, Sweden;

Fish oil from Lipid Technologies Provider AB, Sweden;

Mineral oil (USP) from Sigma-Aldrich. Ethanol (99.5 %) from Kemetyl AB, Sweden.

Distilled water.

Example 1. MCT oil

0.0597 g CMH was mixed with 1.0100 g MCT oil and 0.1201 g ethanol to form the oil phase. 0.7900 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/84.9/10.1 %w/w, w/o : 39.9/60.1 %w/w.

Example 2. Evening primrose oil 0.0591 g CMH was mixed with 0.9992 g evening primrose oil and 0.1209 g ethanol to form the oil phase. 0.7885 g of distilled water was added to the oil phase. RP oil pnase; CMH/oil/ethanol : 5.0/84.7/10.3 %w/w, w/o: 40.1/59.9 %w/w.

Example 3. Sunflower oil 0.0604 g CMH was mixed with 1.0281 g sunflower oil and

0.1218 g ethanol to form the oil phase. 0.8285 g of distilled water was added to. the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/84.9/10.1 %w/w, w/o: 40.6/59.4 %w/w.

Example 4. Coconut oil

0.0610 g CMH was mixed with 1.0403 g coconut oil and 0.1217 g ethanol to form the oil phase. 0.8022 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/85.1/10.0 %w/w, w/o: 39.6/60.4 %w/w.

Example 5. Soybean oil

0.0604 g CMH was mixed with 1.0375 g soybean oil and 0.1213 g ethanol to form the oil phase. 0.8174 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/85.1/9.9 %w/w, w/o: 40.1/59.9 %w/w.

Example 6. Corn oil

0.0604 g CMH was mixed with 1.0253 g corn oil and 0.1210 g ethanol to form the oil phase. 0.8022 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/85.0/10.0 %w/w, w/o: 39.9/60.1 %w/w.

Example 7. Castor oil (comparative)

0.0595 g CMH was mixed with 1.0077 g castor oil and 0.1190 g ethanol to form the oil phase. 0.7981 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/85.0/10.0 %w/w, w/o: 40.2/59.8 %w/w.

Example 8. Fish oil 0.0581 g CMH was mixed with 0.9992 g fish oil and 0.1160 g ethanol to form the oil phase. 0.7887 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 5.0/85.2/9.9 %w/w, w/o: 40.2/59.8 %w/w.

Example 9. Mineral oil 0.0600 g CMH was mixed with 1.1606 g mineral oil and

0.1244 g ethanol to form the oil phase. 0.9649 g of distilled water was added to the oil phase. RP oil phase; CMH/oil/ethanol : 4.5/86.3/9.2 %w/w, w/o: 41.8/58.2 %w/w.

Comparative examples with different sphingolipid materials In order to valuate the properties of different sphingolipid materials the following compositions, Examples 12- 16, were prepared and compared to the compositions according to ^■ the invention, Examples 10-11. The relative proportions, RP, of the carrier components sphingolipid/MCT oil/ethanol are given for each composition in % w/w.

Materials The following sphingolipid materials were used in the examples :

CMH (monohexosylceramide) , prepared from whey concentrate by means of chromatographic fractionation to a purity of >98 %

(Scotia LipidTeknik AB) ; CDH (dihexosylceramide) , prepared from whey concentrate by means of chromatographic fractionation to a purity of >98 % (Scotia

LipidTeknik AB) ; m-SL, milk sphingolipids containing approximately 70 % sphingomyelin, 10 % CMH and 10 % CDH, prepared from whey concentrate by means of chromatographic fractionation (Scotia

LipidTeknik AB) ;

Sphingomyelin, prepared from whey concentrate by means of chromatographic fractionation to a purity of >99 % (Scotia

LipidTeknik AB) ; Glucosylceramide C8 : 0 (glucosylceramide with a C8 : 0 acy cnam linked to the amide nitrogen) from Avanti Polar Lipids, Inc., USA;

Ceramide C24:0 (ceramide with a C24:0 acyl chain linked to the amide nitrogen) from Avanti Polar Lipids, Inc., USA.

Example 10. CMH

0.0608 g CMH was mixed with 1.7676 g MCT oil and 0.2026 g ethanol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form the oil phase. When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature, 1.0048 g of distilled water was weighed into the glass vial . The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial. The resulting emulsion was a macroscopically homogeneous w/o-emulsion of cream-like consistency. RP oil phase; CMH/MCT oil/ethanol : 3.0/87.0/10.0 %w/w, w/o : 33.1/66.9 %w/w.

Example 11. CMH without ethanol

0.0666 g CMH was mixed with 2.1558 g MCT oil in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form the oil phase. When brought back to room temperature an initially macroscopically homogeneous, turbid oil phase of semi- solid consistency was formed. After the oil phase had attained room temperature, 1.0891 g of distilled water was weighed into the glass vial . The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial . The resulting emulsion was a macroscopically homogeneous w/o-emulsion of cream-like consistency. RP oil phase; CMH/MCT oil : 3.0/97.0 %w/w, w/o : 32.9/67.1 %w/w. Example 12. CDH (comparative)

0.0736 g CDH was mixed with 2.1449 g MCT oil and 0.2567 g ethanol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form a homogeneous oil phase. When brought back to room temperature an initially macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature, 1.2175 g of distilled water was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial . The result was an inhomogeneous emulsion with unemulsified aqueous phase. RP oil phase; CDH/MCT oil/ethanol : 3.0/86.7/10.4 %w/w, w/o : 33.0/67.0 %w/w.

Example 13. m-SL (comparative)

0.0875 g milk sphingolipids was mixed with 2.5452 g MCT oil and 0.2945 g ethanol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form a homogeneous clear oil phase . When brought back to room temperature an inhomogeneous oil phase of milk sphingolipid sediment in MCT oil was formed. After the oil phase had attained room temperature, 15; 509 g of distilled water was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial . The result was a two phase system consisting of one oil phase and one aqueous phase. RP oil phase; milk sphingolipids/MCT oil/ethanol : 3.0/86.9/10.1 %w/w, w/o :

Example 14. Sphingomyelin (comparative)

0.0840 g sphingomyelin was mixed with 2.4467 g MCT oil and 0.2796 g ethanol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form a homogeneous clear oil phase. When brought back to room temperature an inhomogeneous milky oil phase of sphingomyelin sediment in MCT oil was formed. After the oil phase had attained room temperature, 1.3840 g of distilled water was weighed into the glass vial . The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial . The result was a two phase system consisting of one oil phase and one aqueous phase. RP oil phase; sphingomyelin/MCT oil/ethanol : 3.0/87.1/9.9 %w/w, w/o : 33.0/67.0 %w/w.

Example 15. Glucosylceramide C8 : 0 (comparative)

0.0279 g glucosylceramide C8 : 0 was mixed with 0.8140 g MCT oil and 0.0917 g ethanol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form the oil phase . When brought back to room temperature an inhomogeneous grainy oil phase was formed. After the oil phase had attained room temperature, 0.4933 g of distilled water was weighed into the glass vial . The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial . The result was an inhomogeneous milky, grainy mixture of oil and aqueous phases. RP oil phase; glucosylceramide C8:0/MCT oil/ethanol : 3.0/87.2/9.8 %w/w, w/o : 34.6/65.4 %w/w.

Example 16. Ceramide C24 : 0 (comparative) 0.0315 g ceramide C24 : 0 was mixed with 0.9210 g MCT oil and 0.1044 g ethanol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form the oil phase. When brought back to room temperature an inhomogeneous grainy oil phase was formed. After the oil phase had attained room temperature, 0.5275 g of distilled water was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial. The result was an inhomogeneous mixture of oil and aqueous phases. RP oil phase; ceramide C24:0/MCT oil/ethanol : 3.0/87.1/9.9 %w/w, w/o : 33.3/66.7 %w/w. Examples of compositions with a bioactive substance or a cosmetic ingredient

The following examples demonstrate the ability of the w/o-emulsion of the present invention to incorporate cosmetic ingredients and bioactive substances . The examples also demonstrate the versatile ways of incorporating a cosmetic or bioactive substance; by dissolving the substance in the aqueous phase, Examples 17-26; by dissolving the substance in the oil phase, Example 27 and 28; or by suspending the substance in the emulsion, Example 29. The procedure for preparing the different compositions was the same in Examples 17-26. Monoglycosylceramide, oil and ethanol were mixed in a sealed 10 ml glass vial and stirred at 80 °C for 10 minutes to form a homogeneous oil phase. When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature the aqueous phase was weighed into the glass vial . The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial. The resulting emulsion was in all examples a macroscopically homogeneous w/o-emulsion of cream-like consistency. The relative proportions of the oil phase components (RP oil phase) and the ratio aqueous phase/oil phase (w/o) as well as the total concentration of cosmetic or bioactive substance are given in all examples .

Materials

Monohexosylceramide (CMH) was prepared from whey concentrate by means of chromatographic fractionation to a purity of >96% from Scotia LipidTeknik AB, Sweden.

MCT oil (medium chain triglyceride oil) from Croda Oleochemicals, England.

Ethanol (99.5 %) from Kerne yl AB, Sweden. Distilled water. The cosmetic ingredients and bioactive substances were:

Aminolevulinic acid hydrochloride [5451-09-2] from Sigma- Aldrich;

Ascorbic acid (vitamin C) [50-81-7] from Sigma-Aldrich; Aspartame [22839-47-0] from AB R. Lundberg, Sweden. (Model for a small peptide) ;

Lithium succinate [16090-09-8] from J. Pickles & Sons, UK;

Methyl nicotinate [93-60-7] from Sigma-Aldrich;

Pyridoxine hydrochloride (Vitamin B6 hydrochloride) [58-56-0] from Sigma-Aldrich;

Scopolamine hydrochloride [55-16-3] from Sigma-Aldrich;

Glycerol [56-81-5] from Apoteksbolaget AB, Sweden;

Lactic acid sodium [867-56-1] from Sigma-Aldrich;

Carbamide (Urea) [57-13-6] from Apoteksbolaget AB, Sweden; -Tocopherol (vitamin E) [10191-41-0] from Fluka;

Coenzyme Q₁₀ [303-98-0] from Sigma-Aldrich;

Metronidazole benzoate [13182-89-3] from Jucker Pharma, Sweden.

Example 17. Aminolevulinic acid dissolved in the aqueous phase 0.0849 g CMH was mixed with 1.8284 g MCT oil and 0.2146 g ethanol to form the oil phase. 1.8370 g of a 19.8 %w/w aminolevulinic acid hydrochloride pH 3 buffered aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 4.0/85.9/10.1 %w/w, w/o: 46.3/53.7 %w/w. Total concentration of aminolevulinic acid hydrochloride 9.2 %w/w.

Example 18. Ascorbic acid dissolved in the aqueous phase

0.0735 g CMH was mixed with 1.2551 g MCT oil and 0.1495 g ethanol to form the oil phase. 0.9903 g of a 10.0 %w/w ascorbic acid aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/84.9/10.1 %w/w, w/o: 40.1/59.9 %w/w. Total concentration of ascorbic acid 4.0 %w/w.

Example 19. Aspartame dissolved in the aqueous phase 0.0575 g CMH was mixed with 0.9833 g MCT oil and 0.1154 g ethanol to form the oil phase. 0.7745 g of a 3.0 %w/w aspartame aqueous solution was added to the oil phase . R on phase; CMH/MCT oil/ethanol : 5.0/85.0/10.0 %w/w, w/o: 40.1/59.9 %w/w. Total concentration of aspartame 1.2 %w/w.

Example 20. Lithium succinate dissolved in the aqueous phase

0.0750 g CMH was mixed with 1.2803 g MCT oil and 0.1515 g ethanol to form the oil phase. 1.0071 g of a 10.0 %w/w lithium succinate aqueous solution was added to the oil phase . RP oil phase; CMH/MCT oil/ethanol : 5.0/85.0/10.1 %w/w, w/o: 40.1/59.9 %w/w. Total concentration of lithium succinate 4.0 %w/w.

Example 21. Methyl nicotinate dissolved in the aqueous phase

0.1349 g CMH was mixed with 1.3849 g MCT oil and 0.1684 g ethanol to form the oil phase. 2.5400 g of a 0.83 %w/w methyl nicotinate aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 8.0/82.0/10.0 %w/w, w/o: 60.1/39.9 %w/w. Total concentration of methyl nicotinate 0.50 %w/w.

Example 22. Pyridoxine hydrochloride dissolved in the aqueous phase

0.0457 g CMH was mixed with 0.0117 g cholesterol, 0.9805 g MCT oil and 0.1127 g ethanol to form the oil phase. 0.8001 g of a 10.0 %w/w pyridoxine hydrochloride aqueous solution was added to the oil phase. RP oil phase; CMH/cholesterol/MCT oil/ethanol : 4.0/1.0/85.2/9.8 %w/w, w/o: 41.0/59.0 %w/w. Total concentration of pyridoxine hydrochloride 4.1 %w/w.

Example 23. Scopolamine hydrochloride dissolved in the aqueous phase 0.0575 g CMH was mixed with 0.9875 g MCT oil and 0.1145 g ethanol to form the oil phase. 0.7927 g of a 7.6 %w/w scopolamine hydrochloride aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/85.2/9.9 %w/w, w/o: 40.6/59.4 %w/w. Total concentration of scopolamine hydrochloride 3.1 %w/w. Example 24. Glycerol dissolved in the aqueous phase

0.0969 g CMH was mixed with 1.6501 g MCT oil and 0.1990 g ethanol to form the oil phase. 1.9618 g of a 4.0 %w/w glycerol aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/84.8/10.2 %w/w, w/o: 50.2/49.8 %w/w. Total concentration of glycerol 2.0 %w/w.

Example 25. Lactic acid sodium dissolved in the aqueous phase

0.0977 g CMH was mixed with 1.6595 g MCT oil and 0.1965 g ethanol to form the oil phase. 1.9611 g of a 10.0 %w/w lactic acid sodium aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/84.9/10.1 %w/w, w/o: 50.1/49.9

%w/w. Total concentration of ascorbic acid 5.0 %w/w.

Example 26. Carbamide dissolved in the aqueous phase

0.1053 g CMH was mixed with 1.7920 g MCT oil and 0.2138 g ethanol to form the oil phase. 2.1103 g of a 8.0 %w/w carbamide aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/84.9/10.1 %w/w, w/o: 50.0/50.0 %w/w. Total concentration of carbamide 4.0 %w/w.

Example 27. α-Tocopherol dissolved in the oil phase

0.1018 g CMH was mixed with 1.6507 g MCT oil, 0.2082 g ethanol and 0.0998 g -tocopherol in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form a homogeneous oil phase . When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature, 2.1762 g of distilled water, the aqueous phase, was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial, to form a macroscopically homogeneous w/o-emulsion of cream-like consistency. Relative proportions; CMH/MCT oil/ethanol : 5.2/84.2/10.6 %w/w, aqueous phase/oil phase : 51.4/48.6 %w/w. Total concentration of α-tocopherol 2.4 %w/w.

Example 28. Coenzyme Q_ι0 dissolved in the oil phase 0.1109 g CMH was mixed with 1.7820 g MCT oil, 0.2155 g ethanol and 0.1058 g coenzyme Q₁₀ in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form a homogeneous oil phase. When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature, 1.5056 g of a 5.0 %w/w NaCl aqueous solution, the aqueous phase, was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial, to form a macroscopically homogeneous w/o-emulsion of cream-like consistency. Relative proportions; CMH/MCT oil/ethanol : 5.3/84.5/10.2 %w/w, aqueous phase/oil phase : 40.5/59.5 %w/w. Total concentration of coenzyme Qι₀ 2.8 %w/w.

Example 29. Metronidazole benzoate suspended in the carrier

0.0368 g CMH was mixed with 0.9401 g MCT oil, 0.1250 g ethanol, 0.1250 g glycerol and 0.8037 g metronidazole benzoate in a sealed 10 ml glass vial. The mixture was stirred at 80 °C for 10 minutes to form a homogeneous oil phase. When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. As soon as the oil phase had attained room temperature, 0.5022 g of distilled water, the aqueous phase, was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial, to form a macroscopically homogeneous w/o emulsion of cream-like consistency. Relative proportions; CMH/MCT oil/ethanol/glycerol : 3.0/76.6/10.2/10.2 %w/w, aqueous phase/oil phase : 19.8/80.2 %w/w. Total concentration of metronidazole benzoate 31.7 %w/w. Examples demonstrating the emulsifying effect of monoglycosylceramide at high ionic strengths and extreme pH values

The high emulsifying effect of monoglycosylceramide in compositions of the present invention is demonstrated in the following examples, where macroscopically homogeneous w/o- emulsions of cream-like consistency are prepared even when the aqueous phase has a considerable high ionic strength or has a pH value far from neutral pH. The procedure for preparing the different compositions was the same in all examples. Monoglycosylceramide, oil and ethanol, the same as in the previous examples, were mixed in a sealed 10 ml glass vial and stirred at 80 °C for 10 minutes to form a homogeneous oil phase. When brought back to room temperature a macroscopically homogeneous, turbid oil phase of semi-solid consistency was formed. After the oil phase had attained room temperature the aqueous phase was weighed into the glass vial. The mixture was then shaken vigorously at room temperature on a vortex apparatus, with a magnetic stirring bar included in the glass vial . The resulting emulsion was in all examples a macroscopically homogeneous w/o- emulsion of cream-like consistency.

Example 30. NaCl

0.0767 g CMH was mixed with 1.2996 g MCT oil and 0.1531 g ethanol to form the oil phase. 1.5214 g of a 25.4 %w/w NaCl aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/85.0/10.0 %w/w, w/o: 49.9/50.1 %w/w. Total concentration of NaCl 12.7 % w/w.

Example 31. CaCl₂

0.0782 g CMH was mixed with 1.3245 g MCT oil and 0.1568 g ethanol to form the oil phase. 1.5555 g of a 7.0 %w/w CaCl₂ aqueous solution was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 5.0/84.9/10.1 %w/w, w/o : 49.9/50.1 %w/w. Total concentration of CaCl₂3.5 %w/w. Example 32. 0.1 M HC1

0.1045 g CMH was mixed with 1.9804 g MCT oil and 0.1336 g ethanol to form the oil phase. 0.3754 g of 0.1 M HC1 (pH 1) was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 4.7/89.3/6.0 %w/w, w/o : 14.5/85.5 %w/w.

Example 33. 0.1 M NaOH

0.1041 g CMH was mixed with 1.9723 g MCT oil and 0.1218 g ethanol to form the oil phase. 0.4014 g of 0.1 M NaOH (pH 13) was added to the oil phase. RP oil phase; CMH/MCT oil/ethanol : 4.7/89.7/5.5 %w/w, w/o : 15.4/84.6 %w/w.

TEST OF STABILITY OF THE FORMULATION OF EXAMPLE 17 To demonstrate the ability of the w/o-emulsion of the present invention to incorporate substances, which demand extreme pH values to retain stable, the stability of aminolevulinic acid was examined by means of high performance liquid chromatography. The pharmaceutical formulation of Example 17 was stored at room temperature for approximately 3 months, protected from light, before the analysis was made. It is well known that aminolevulinic acid is rapidly degraded in aqueous solutions having a pH value higher than about 3.

Materials

HPLC Column Ultrasphere C8, 150*4.6 mm, 5μ, Beckman, USA.

Guard column Zorbax SB-C18, 12.5*4.6 mm, 5μ, Agilent Technologies, USA. Phosphoric acid from Merck, Germany.

1-octanesulphonic acid from Sigma-Aldrich. Acetonitrile from Merck Eurolab AB, Sweden. Hexane from Merck Eurolab AB, Sweden. Isopropanol from Merck Eurolab AB, Sweden. Liquid chromatographic system; Dionex P580 pump 1 ml/min, Auto sampler Dionex Gina 50 100 μl and Lamda UV detector SPD-6A at 263 nm. The signal from the detector was recorαeα oy Gynkotek Chromeleon Chromatography Data System version 4.32.

Mobile phase; 90 % 50 πiM phosphoric acid containing 5 mM 1-octanesulphonic acid and 10 % Acetonitrile.

Analysis

Approximately 200 mg of the topical formulation of Example 17 was accurately weighed and dissolved in 4 ml hexane/isopropanol: 4/1 by volume in a test tube, 2 ml distilled water was added and the mixture was vigorously shaken and slightly heated for 10 to 20 seconds in a water bath at 50 °C . After centrifugation at 3500 rpm for 1 min the upper organic layer was discarded and the water phase was washed twice more with 4 ml of the hexane/isopropanol mixture. The resulting water phase was diluted up to 10 ml with the mobile phase and injected on the chromatographic system described above. The concentration of aminolevulinic acid concentration in the samples was evaluated by means of a three point standard curve (1-3 mg/ml) . The sample was prepared in duplicate. The analysis showed a 92 and 94 % recovery of aminolevulinic acid, respectively.

CONCLUSIONS FROM THE EXPERIMENTS

- The surprisingly easy method of the preparation of the w/o-emulsion, and the possibility to use several different oils is demonstrated in Examples 1-9.

- The unique properties of monoglycosylceramides compared to diglycosylceramides, unglycosylated ceramides and other sphingolipid materials are demonstrated by the Comparative examples 10-16. - The capacity of the topical composition to incorporate cosmetic ingredients or bioactive substances, is clearly demonstrated in Examples 17-29, in which about 0.5-32 % by weight of thirteen different substances successfully have been incorporated. In all cases the result is a macroscopically homogeneous, cream-like topical formulation. - The surprising property of the topical composition co form macroscopically homogeneous w/o-emulsions of cream-like consistency even when the aqueous phase has a considerably high ionic strength or has a pH value far from neutral pH, is demonstrated in the Examples 30-33.

- The ability of the w/o-emulsion of the present invention to incorporate substances, requiring extreme pH values to retain stable, is demonstrated in Test of stability of the formulation of Example 17.

Claims

1. A topical w/o-emulsion composition comprising an oil phase and an aqueous phase dispersed in the continuous oil phase, wherein the oil phase contains at least one non-polar oil, and a polar lipid material as emulsifier, characterised in that the polar lipid material is one or more monoglycosylceramides .

2. A composition according to claim 1, characterised in consisting of an oil phase of 60-99.9 % by weight of at least one non-polar oil in combination with 0.1-40 % by weight of monoglycosylceramide, and an aqueous phase, in a w/o ratio of up to 80/20 by weight.

3. A topical w/o-emulsion composition comprising an oil phase and an aqueous phase dispersed in the continuous oil phase, wherein the oil phase contains at least one non-polar oil, a polar lipid material as emulsifier, and ethanol, characterised in that the polar lipid material is one or more monoglycosylceramides .

4. A composition according to claim 3, characterised in consisting of an oil phase of 30-99.9 % by weight of at least one non-polar oil in combination with 0.1-40 % by weight of monoglycosylceramide, and up to 30 % by weight of ethanol, and an aqueous phase, in a w/o ratio of up to 80/20 by weight.

5. A composition according to any of claims 1-4, characterised in that the content of monoglycosylceramide is 0.1-20 % by weight of the oil phase, preferably 0.2-10 %.

6. A composition according to any of claims 1-5, characterised in that the acyl chain linked to the amide nitrogen of the monoglycosylceramides is derived from unsaturated or saturated fatty acids having 10-28 carbon atoms.

7. A composition according to any of claims 1-6, characterised in that the sphingoid base of the monoglycosylceramides has 6-28 carbon atoms.

8. A composition according to any of claims 1-7, characterised in that the monoglycosylceramide is monohexosylceramide .

9. A composition according to claim 8, characterised in that the monohexosylceramide is monoglucosylceramide or monogalactosylceramide .

10. A composition according to claim 8 or 9, characterised in that the monohexosylceramide is obtainable from bovine milk.

11. A composition according to any of claims 1-10, characterised in that the non-polar oil is selected from the group consisting of triglyceride oil, mineral oil, or a mixture thereof .

12. A composition according to any of claims 1-11, characterised in that the non-polar oil is a triglyceride oil .

13. A composition according to claim 11 or 12, characterised in that the triglyceride oil is selected from the group consisting of medium chain triglyceride oil, sesame oil, evening primrose oil, sunflower oil, coconut oil, soybean oil, corn oil, fish oil, or a mixture thereof.

14. A composition according to any of claims 1-13, which in addition contains one or more additives .

15. A cosmetic formulation for topical administration comprising a composition according to any of claims 1-14 in combination with one or more cosmetic ingredients .

16. A pharmaceutical formulation for topical administration comprising a composition according to any of claims 1-14 in combination with one or more bioactive substances in a pharmaceutically effective amount.

17. A pharmaceutical formulation according to claim 16 for ocular, dental or dermal administration.

18. A pharmaceutical formulation according to claim 16 or 17, characterised in that the bioactive substance is selected from the group consisting of antibiotic, antimicrobial, antiviral, anti-inflammatory, antifungal, antipsoriatic, antiseborr- heic and antitumour drugs, anesthetics, insecticides, antiacne agents, hair growth stimulants, lipids, steroids, hormones, proteins, peptides, amino acids, minerals and vitamins.

19. A composition or formulation according to any of claims 1-18, characterised in being a cream, an ointment or a lotion.