AU631577B2

AU631577B2 - An emulsion

Info

Publication number: AU631577B2
Application number: AU45520/89A
Authority: AU
Inventors: Mark Boyd Tully
Original assignee: IMPILO DRUGS (1966) Pty Ltd
Current assignee: IMPILO DRUGS (1966) Pty Ltd
Priority date: 1988-11-24
Filing date: 1989-11-23
Publication date: 1992-12-03
Anticipated expiration: 2009-11-23
Also published as: IT8922514A1; ZW15689A1; FR2639224A1; GB2226256A; GB2226256B; IT8922514A0; DE3938901A1; IT1241676B; AU4552089A; GB8926488D0

Description

I L. L_ II

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u 457 COMMONWEALTH OF AUSTRALIA Patent Act 1952 COMPLETE S P E C I F I C A T ION

(ORIGINAL)

Class Int. Class Application Number Lodged Complete Specification Lodged Accepted Published Priority: 24 November 1988 Related Art Name of Applicant Address of Applicant Actual Inventor Address for Service IMPI-u DRUGS (1966) (PROPRIETARY)

LIMITED

23 Acutt Avenue, Rosehill, Durban, Natal, Republic of South Africa Mark Boyd Tully F.B. RICE CO., Patent Attorneys, 28A Montague Street, BALMAIN. 2041.

Complete Specification for the invention entitled: "AN EMULSION" The following statement is a full description of this invention including the best method of performing it known to us:r_ 0f la THIS INVENTION RELATES to an emulsion for a base which may be utilized on its own or as a base to which additional ingredients may be added.

According to one aspect of the invention there is provided a topical preparation for nutritious, cosmetic or therapeutic use and comprising a stable emulsion which comprises a stable and substantially homogeneous mixture having a continuous phase comprising a second constituent which is a polyhydric alcohol, and a discontinuous phase comprising a first constituent which is a hydrocarbon wax, gel or oil, and a third constituent which is an emulsifying agent comprising at least one sulphated, higher alcohol having a carbon chain length of from Clo to C 20 in the following proportions of the total mass of the first and second constituents: 10 to 40% (first constituent) 60 to 90% (second constituent) 1 to 14 (third constituent); and P 1 2 dispersed within said mixture, 0 to 60% by mass of water based on the total mass of the first, second and third constituents.

By "stable" emulsion is meant an emulsion which does not break down at least at temperatures in the range to which it is to be exposed, namely 0 C to +120 0

C.

oo .15 1 B i i Preferably the emulsion comprises not more than 40% by mass of the water.

Any suitable hydrocarbon wax, gel or oil may be used. A particularly suitable material is petroleum jelly. A preferred petroleum jelly is white petroleum jelly B.P. It is a mixture of purified, bleached, largely saturated hydrocarbons.

In its normal semi-solid state it is a two-phase colloidal system or gel comprising high molecular weight hydrocarbons dispersed in microcrystalline or amorphous waxes. Alternatively, petrolatums (eg.

yellow petrolatum) can be used. Details of these materials are set out in the examples which follow.

The polyhydric alcohol conveniently may be an aliphatic polyhydric alcohol, eg. glycerine or sorbitol or propylene glycol.

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I r J L~ 3 The emulsifier may be an anionic selfemulsifying wax which may be a partially sulphated mixture of cetyl and stearyl alcohols. A particularly suitable emulsifier is emulsifying wax BP which is obtainable, for example, as LANETTE SX, CRODEX A, CYCLOCHEM or CYCLONETTE WAX. "LANETTE", "CRODEX", "CYCLOCHEM" and "CYCLONETTE" are believed to be registered trade marks, in South Africa, of Henkel Kommanditgesellschaft Auf Aktien, Croda (UK), Witco (UK) and Witco (UK) respectively.

A stable substantially anhydrous emulsion according to the invention generally comprises approximately 1 to 14% of the emulsifier based on the total mass of the first and second constituents.

A typical substantially anhydrous emulsion according to the invention may comprise petroleum jelly, glycerine and emulsifying wax BP in the following proportions of the total mass of the first and second constituents 20 to 30% (preferably about 25%) 70 to 80% (preferably about 72%) to 10% (preferably about Whenever the term "substantially anhydrous" is used herein in relation to the emulsion of the present invention, it should be understood as being descriptive of an emulsion which 20 i 6.

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2 L) 040 0 04 0c rPL~q Ir0 o OL'j s nxnn*~, contains only such limited and insignificant amounts of water, if any, as happens to have been included in those constituents from which it has been prepared. For example, commercially available polyhydric alcohols generally contain not more than 2% by mass of water, and commercially available anionic emulsifying waxes which are preferred emulsifying agents for the emulsion of the present invention, generally contain not more than 1% by mass of water. Certainly no additional water is included as a constituent during the preparation of a "substantially anhydrous" emulsion of the present invention.

0 0 000 0 o o 0 02 .0I 0 0 00 so 0 00 i 0 0 0 e a. a: 6 Whenever the term "substantially homogeneous" is used herein in relation to the present invention, it should be understood as being descriptive of such uniformity of dispersion which generally characterises emulsions.

The emulsion provided by the invention is an oil-in-alcohol emulsion wherein the hydrocarbon wax, gel or oil is the disperse phase and the polyhydric alcohol is the continuous phase. Without being bound by theory, it appears that the droplets of the disperse phase are coated with the emulsifying agent and these coated droplets are dispersed in the continuous phase to provide a stable product.

By varying the proportion of the wax, gel or oil, the viscosity of the emulsion can be adjusted. If -the proportion is increased, the viscosity is increased. If the proportion is decreased, the viscosity is decreased.

A preferred emulsion according to the invention comprises a first constituent which is a petroleum jelly; a second constituent which is glycerine; a third constituent which is an emulsifying agent comprising a colloid disperse mixture comprising about 90 parts by mass cetearyl alcohol and about 10 parts by mass sodium alkyl sulphate; and 0 to 60% by mass of water based on the total mass of the first, second and third constituents, and the first, second and third constituents are present in the following proportions by mass based on the total mass of the f irst and second constituents: 20 to 30% 70 to 80'0 3.5 to The emulsion conveniently can be prepared by having a mixing tank which is supplied with the constituents from their own separate tanks. The $0 0 0 0 440 0 0 0000 0 0 00 0 00 0440 04 0 00 ri -r I 4 a 4 44« ,a6 a 4 6 *444 2Q 4 t

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i polyhydric constituent (such as glycerine) conveniently may be heated to a temperature of about to 90 0 C and the other main constituent, such as petroleum jelly, can conveniently be heated to about 55 to 90 0 C. The emulsifier conveniently can then be mixed with the petroleum jelly and thereafter this mixture incorporated into a final base mix with the glycerine. Mixing may be effected down a spiral mixer.

According to another aspect of the invention there is provided a method of preparing a stable emulsion suitable for nutritious, cosmetic or therapeutic use on the human skin or hair and comprising a first constituent which is a hydrocarbon wax, gel or oil and a second constituent which is a polyhydric alcohol, which includes heating the first constituent to a temperature of from 550to admixing to the heated first constituent, a third constituent which is an emulsifying agent comprising at least one sulphated higher alcohol having a chain length of from CIO to C 20 heating the second constituent to a temperature of from 55 0 C to 90 0 C; and forming a substantially homogeneous mixture by mixing the heated mixture of the first and second constituents with the heated second constituent in 7 the following proportions of the total mass of the first and second constituents: 10 to 40% (first constituent) 60 to 90% (second constituent) 1 to 14% (third constituent).

The preferred mixing temperature for each of the hydrocarbon wax, gel or oil and polyhdric alcohol is 75 to 80 0 C. Preferably, these constituents are at substantially the same temperature when they are mixed together.

The heating together of the constituents and mixing of them enables a homogeneous mixture of the hydrocarbon wax and the polyhydric alcohol to be obtained without having water present. After the mixing of the constituents within the temperature range indicated, the mixture is cooled to give the homogeneous product. The product at room temperature usually is a soft gel.

If desired, other materials can be added, for example perfumes, medicaments or other active pharmaceutical ingredients, active cosmetic ingredients or the like. Particular examples are antimycotic agents such as Amphotericin (eg in an amount constituting about 3% by mass of the emulsion), a a i a a. a ar a a a i; i o i ii a oI i^ 0 *S i 14 a i I t r_ *i I- e 7 Clotrimazole (eg in an amount constituting about 1% by mass of the emulsion), Econazole (eg about and Miconazole (eg about anti-inflammatory agents such as betamethasone-17-valerate (eg about hydrocortisone (eg about Prednisolone (eg about Clobetasone butyrate (eg about and Indomethacin (eg about antiseptic agents such as Cetrimide (eg about and Cetylpyridium chloride (eg about and 0090 00 0 o 0o Do 0 2 oou 0 0 00 0 00 0 00 0 o i 0 a 0o 0 0 o as oa I, 6o 0 0 00 0 0 a os a B O 0 a 6 sunscreen agents/ultra-violet absorbers such as Sulisobenzone (eg about ethylmexyl p-methoxyannamate (eg about and benzyl salicylate (eg about 2 to Either water soluble, or oil soluble additives can be added to the emulsion according to the invention and mixed in at room temperature to provide a homogeneous stable product.

The emuls provided by the invention may :.ic base to be applied to the be utilized as a c *i 9 skin. It may also be utilized for the administration of other cosmetic materials or for the administration of pharmaceutically active materials topically to a patient. Furthermore, it i 5 can be used as a base for hair straighteners. Where the emulsion is intended for use with medicaments, the preferred polyhydric alcohol constituent may be propylene glycol propan-1,2-diol, ie C 3

H

8 0 2 Thus the invention extends further to t.e use of an emulsion according to the invention for i preparing a substance or composition for application to the human skin or hair, and yet further to a substance or composition for nutritious cosmetic or therapeutic application to the human skin or hair when prepared from an emulsion according to the i, invention.

S*,

Furthermore and as mentioned above, if it a 4* is to be used as a sunburn cream, it may contain l f t t other materials to screen the effectiveness of the U l 20 sun.

i 44 S The following tables a) and b) give details of the content of white petroleum jelly and yellow petrolatum respectively.

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W E WHITE PETROLATUMS WAXREX 521 (STANDARD WHITE)

WHITE

PETROLATUM BP/USP 76613 PROPERTIES METHOD SPECIFICATION TYPICAL Colour, Lovibond IP 17 1.5 Y/0.3 R max 0.5 Y/O,1 R cell) hot Drop Melting Pt. "C IP 31 38 56 Penetration at 25°C, ASTM 150 180 160 dmm D937 Viscosity, mm 2 /sec at ASTM no set 11.9 100"C D445 specification Light Absorption BP 0.50 max 0,06 (0.05% solh at 290 nm) Foreign Organic Matter BP No acrid odour Pass evolved Sulphated Ash BP 0.1% max Pass Acidity/Alkalinity BP/UP neutral to Pass litmus under test conditions Specific Gravity at USP 0.815-0.880 0.877 60/60 F Organic Acids USP Not more than Pass 400 p1 of 0.100 N NaOH Penetration, dmm ASTM 100 300 160 Fixed Oils, Fats and USP No oily or solid Pass Resins matter separates after test Residue on Ignition USP 0.1% max Pass 44i 44 Cf., £4 4 k o< 44,4r 4 44 '4 PETROLATUMS (YELLOW PETROLATUMS) WAXREX 562 WAXREX 541 PETROLATUM USP YELLOW YELLOW (YELLOW PETROLATUM) (YELLOW SC) (STANDARD

YELLOW)

PROPERTIES METHOD 76796 76814 Colour, Lovibond IP 17 35y 3R 15Y cell) Max. Cell)

ASTM

Melting Point, *C D127 53 58 58 Penetration at 25"C ASTM 210 245 160 180 D937 Viscosity, mm 2 /sec at ASTM 10.5 16.5 6.5 8.25 98.9°C D445 Light Absdrption BP absorbence at absorbence at 29 nm less than 29 nm less than 0.75 0.75 Foreign Organic Matter BP/USP no acrid cdour no acrid odour evolved evolved Sulphated Ash BP 0.1 max. 0.1 max.

Specific Gravity at USP 0.815-0.880 0.815-0.880 15.6/15.6°C Organic Acids USP not more than not more than 4001. of 0.100N 4001. of 0.100N NaOH NaOH Penetration ASTM 150-180 dmm 150-180 dmm Fixed Oils, Fats USP no oily or solid no oily or solid and Resins matter separates matter separates after test after test r .'i i Ii i

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12 "WAXREX" is a trade mark of TEXACO which is a German Company.

"76796", "76814" and "76613" identification numbers for the specified in Tables and are TEXACO's petrolatum's "LOVIBOND" is a trade name for an instrument supplied by British Drug Houses and used for the purpose of comparing and matching colours.

"ASTM D937" is an abbreviation for American Society of Testing Materials, test D937.

"IP17" is an abbreviation for "International Pharmacopoeia, test no. 17".

"IP31" is an abbreviation for "International Pharmacopoeia, test no. 31" "BP" is an abbreviation for "British Pharmacopoeia".

"USP" is an abbreviation for "United Pharmacopoeia".

is an abbreviation for "yellow", and States Ic i i 13 is an abbreviation for "red". Thus "1.5Y/0.3 R max" should be read as "1.5 yellow/0.3 red maximum".

The invention is now described by way of the following non-limiting example in which the hydrocarbon wax, gel or boil (ie the first i constituent) is white petroleum jelly, the polyhydric alcohol (ie the second constituent) is glycerine, and the emulsifying agent (ie the third constituent) is LANETTE SX.(Registered Trade Mark) Glycerine is a syrupy liquid which absorbs moisture from the air and is known chemically as propan-l,2,3-triol and has the formula C 3

H

8 0 3 LANETTE SX comprises a colloid disperse i mixture composed of 90 parts "LANETTE" 0 to 10 parts S 15 of sodium alkyl sulphate. Its CTFA designation is cetearyl alcohol and sodium lauryl sulphate. It is a yellow to white granulated mass containing j approximately 99% of fats, 0.235 to 0.279 mval-g, a u maximum of 1.4% of inorganic salts, a maximum of 1.0% water, a pH value (as a 1% suspension) of to 8 and a solidification temperature of 50 to 54°C.

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(I16 LI I I t I I 4 r- 14 "CTFA" is an abbreviation for Cosmetic Toiletry and Fragrances Association.

The mixing of the constituents can be carried out using the apparatus illustrated in the accompanying drawings in which FIGURE 1 is a schematic representation of an apparatus for preparing an emulsion according to the invention; and FIGURE 2 is a three dimensional view of a component of the apparatus.

In Figure 1, reference numeral generally indicates an apparatus for preparing an emulsion according to the invention.

For brevity and ease of description, the apparatus is described in its in use orientation as shown as Figure 1, and words such as "horizontal", "top", "above", etc. which generally indicate relative position or direction, should not be construed as limiting.

The apparatus 10 includes two supply tanks 12 and 14, each having capacity for 285 kg glycerine and a supply tank 16 which can hold 196 kg petroleum !i; i a ii I i !i i!

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jelly. These tanks may be any heating vessel.

Preferably they are electric pots (eg Vulcan pots) which facilitate fine control of temperatures.

The tanks 12, 14, 16 communicate with a mixing tank 18 which open at the top, via connecting pipes 20 and a manifold 22. Tank 18 has a maximum capacity of 1000 kg. The connecting pipes 20 are fitted with valves 24 to permit manual adjustment of the rate of discharge of the contents of the tanks 12, 14, 16.

The manifold 22 includes a spiral mixer (not shown) with five 3600 turns for mixing the contents of the supply tanks 12, 14, 16 before feeding into the mixing tank 18. The spiral mixer has been specially designed to give an appropriate primary mix of the hot liquid before it enters the mixing tank 18. The diameter of the spiral mixer should be large enough to accommodate the flow of liquid from the tanks 12, 14 and 16 when the valves 24 are fully opened. The lower end portion of the spiral mixer is disposed at an angle of 300 to the horizontal above the open mixing tank 18.

4 iz 1;- An electric motor driven pump 26 is prQvided for recirculating the contents of the mixing tank 18 by pumping the contents out of an opening 28 in the bottom wall of the tank 18 and to feed back into the tank 18 adjacent its top opening, via a pipe 30 which has a diameter in the range of from 12 to 40 mm.

The preferred size of the motor (not shown) is a 1.1 kw, 50 Hz, 1390 rpm motor to which is fitted a gearing unit for reducing the revolutions to 226 rpm. The motor drives a circular-section cylinder 32 of hard nitrile rubber which is rotatable about its longitudinal axis and in a direction indicated by arrow 34. The cylinder 32 is a snug fit within a tubular casing or stator (not shown). The outer surface 36 of the cylinder 32 defines a spiral groove 38 which extends between the opposed ends of the cylinder 32. In use, the cylinder 32 is driven at approximately 226 rpm. The contents of the mixing tank 18 enter the pump 26 and are urged along the groove 36 in the direction iricated by arrow 40, before entering the pipe and returning to the mixing tank 18.

CiaI 6.

r.- 17 The following non-limiting example illustrates the invention.

Each of the tanks 12 and 16 were charged with 280 kg of glycerine and the tank 14 was charged with 196 kg petroleum jelly. The glycerine and petroleum jelly in these tanks were heated slowly up to a temperature of between 73 and 75 0 C. 38 kg of LANETTE SX supplied by Henkel SA (Pty) Ltd (situated in Transvaal, South Africa) were then added to the petroleum jelly in the tank 14 and the resulting mixture was agitated until the LANETTE SX dissolved in the petroleum jelly.

When the contents of the tanks 12, 14, 16 had reached the desired temperature and the LANETTE SX had been dissolved in the petroleum jelly, the p. glycerine and petroleum jelly/LANETTE SX mixture were discharged from the tanks at such rates ,i (adjustable via valves 24) so as to maintain, as far Ki as possible, the same ratio by mass of glycerine and petroleum jelly in the tanks 12, 14, 16 as was provided initially.

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i 20

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i S The glycerine and petroleum jelly were gravity fed into the mixing tank 18 via the spiral mixer within the manifold 22.

When discharge from the tanks 12, 14, 16 was initiated, the pump 30 was started and thereby circulation of the glycerine/petroleum jelly/LANETTE SX mixture was initiated.

Once the contents of the tanks 12, 14, 16 had been totally discharged into the mixing tank 18, the resulting mixture was circulated for approximately one hour. The mixture became lighter in colour and assumed a sheen as it was forced through the cylinder 32. It is believed that the relative narrowness of the pipe 30 through which the mixture was pumped as it returned to the tank 18, contributed to the lightening in colour.

After circulating for about one hour, the resulting product was left to stand for several hours, or at least until the temperature of the mixture in the mixing tank 18 had reduced to approximately 30 to 35 0

C.

Perfume was then added.

55S0

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19 i The mixture was allowed to cool to room temperature. It was left to stand during this cooling period except for a short time every couple of hours when mixing was effected by operating the pump 30 to circulate the mixture.

The emulsion product was in the form of a slightly tacky, soft grey to white gel which proved to be extremely stable. It was found, for example, that the product could be boiled and even heated to temperatures above 120 0 C without any perceptible separation of the constituents. On re-cooling to room temperature, the product in original form was identified. Furthermore, freezing of the product for a number of days did not cause separation in either the frozen state or when it was returned to room temperature. Thus fluctuations in temperature did not adversely affect the stability of the product.

i In other example in which mixing of the I 20 petroleum jelly and glycerine did not include subjecting the mixture thereof to friction and pressure similar to that which the mixture from tank 'I1 18 was subjected to when it was forced through the cylinder 32 and pipes 30, the colour of the emulsion ri product was darker, the texture was not as fine, and the sheen, if any, was greatly reduced.

The anhydrous product does not support bacterial growth and, furthermore, requires and contains no preservatives. Water may be added in quantities of up to 65% without requiring any preservative. This appears to be due to the preservative action of glycerine.

In its anhydrous or hydrous state, the product of the invention has extremely good skin moisturizing properties and can beneficially be applied to the skin or hair. It softens the skin and leaves it with a slight sheen which is particularly noticeable and attractive on darker skins. The glycerine constituents may have a skin lightening effect. It is believed that the product will prove to be particularly suitable for black "Afro" hair styles in that it gels the hair and gives it a shiny black appearance.

The product is a boon to those suffering from dry skin conditions and restores dry, scaly or cracked skin, for example on heels, to a healthy, supple state.

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I; I 7 *7 The emulsion of the invention may further be used as a bath or shower gel. A user thereof spreads a small quantity over his body or face, adds water and rubs the resulting fine, milky lotion into the skin. The skin becomes soft, supple, but not greasy.

Creams comprising the emulsion may include water in quantities of up to 60%, preferably up to and more preferably 20% of the total mass of the first, second and third constituents of the emulsion. These creams may be used as nourishing or sun screen creams, or as vehicles for therapeutic active ingredients, for use as antiseptics, corticosterioids, etc.

Lotions are formed by adding water to the emulsion in quantities of 30 to 92%, preferably to 50% and more preferably 40% of the total mass of the first, second and third constituents of the emulsion. A very smooth lotion is thereby provided and can be used for similar applications as mentioned above for the creams.

In short the emulsion according to the invention at least as exemplified, is a stable II iC

I.I

22 i product which can easily be diluted with oil and/or i i with water to produce many different cosmetic or pharmaceutical preparations including face creams, hand and body lotions, hair care preparatins, medicinal preparations in the forms of gels, creams and lotions and, when diluted with light oils, other products for which it is desired to use a cream base which is free from preservatives. Even in its anhydrous state it has excellent moisturising properties. Furthermore it is non-allergenic and is relatively cheap and easy to prepare.

Claims

1. A method of preparing a nutritionally, cosmetically or therapeutically acceptable stable emulsion which comprises a first constituent which is a hydrocarbon wax, gel or oil and a second constituent which is a polyhydric alcohol, wherein the method includes heating the first constituent to a temperature of from 550C to 90 0 C; admixing to the heated first constituent, a third constituent which is an emulsifying agent comprising at least one sulphated higher alcohol having a chain length of from Cl 0 to C 20 heating the second constituent to a temperature of from 55 0 C to 90 0 C; and forming a substantially homogeneous mixture by mixing the heated mixture of the first and second constituents with the heated second constituent in the following proportions of the total mass of the first and second constituents: 10 to 40% (first constituent) 60 to 90% (second constituent) 1 to 14% (third constituent).

2. A method as claimed in Claim 1, wherein the third constituent is emulsifying wax BP. 24

3. A method as claimed in Claim 1 or Claim 2, wherein the first constituent is a petroleum jelly, the second constituent is glycerine or sorbitol or propylene glycol, the third constituent is a colloid disperse mixture comprising about 90 parts by mass cetearyl. alcohol and about 10 parts by mass sodium alkyl sulphate, and the first, second and third constituents are mixed together in the following proportions by mass based on the total mass of the first and second constituents: 20 to 30% 70 to 3.5 to

4. A nutritionally, cosmetically or therapeutically stable emuls in prepared according to the method as claimed in any one of Claims 1 to 3. An emulsion as claimed in Claim 4 when used for preparing a substance or composition for application to the human skin or hair.

6. A pharmaceutical composition which includes a medicament and, serving as a carrier or vehicle therefor, an emulsion as claimed in Claim 4. q ZE N'

7. A nutritionally, cosmetically or therapeutically acceptable topical preparation comprising a stable emulsion, the stable emulsion comprises a stable and substantially homogeneous mixture having a continuous phase comprising a second constituent which is a polyhydric alcohol, and a discontinuous phase comprising a first constituent which is a hydrocarbon wax, gel or oil, and a third constituent which is an emulsifying agent comprising at least one sulphated, higher alcohol having a carbon chain length of from C 10 to C 20 in the following proportions of the total mass of the first and second constituents: 10 to 40% (first constituent) 60 to 90% (second constituent) 1 to 14% (third constituent); and dispersed within said mixture, 0 to 60% by mass of water based on the total mass of the first, second and third constituents.

8. An emulsion as claimed in Claim 7, wherein 2C the first constituent comprises a petroleum jelly and the polyhydric alcohol comprises glycerine or sorbitol or propylene glycol. ~11 vi -r1< 26

9. A nutritionally, cosmetically or therapeutically acceptable topical preparation comprising a stable emulsion, the stable emulsion comprises a first constituent which is a petroleum jelly; a second constituent which is glycerine; a third constituent which is an emulsifying agent comprising a colloid disperse mixture comprising about 90 parts by mass cetearyl alcohol and about 10 parts by mass sodium alkyl sulphate; and 0 to 60% by mass of water based on the total mass of the first, second and third constituents, and the first, second and third constituents are present in the following proportions by mass based on the total mass of the first and second constituents: 20 to 30% 70 to 80% 3.5 to A pharmaceutical composition which includes a medicament and, serving as a carrier or vehicle therefor, an emulsion as claimed in any one of claims 7 to 9.

11. An of an emulsion as claimed in any one of claims 7 to 9, when used for preparing a substance or composition for application to the human skin or hair. 27

12. A new. stable emulsion, substantially as herein described with reference to the accompanying description.

13. A new method of preparing a stable emulsion comprising a hydrocarbon wax, gel or oil and a polyhydric alcohol, substantially as herein described with reference to the accompanying description. Dated this 24 day of September 1992 IMPILO DRUGS (1966) (PROPRIETARY) LIMITED SPatent Attorneys for the Applicant: F B RICE CO /i cV