WO1993023482A1

WO1993023482A1 - Coated particles

Info

Publication number: WO1993023482A1
Application number: PCT/EP1993/001178
Authority: WO
Inventors: Edward Galley; Nicola Anne Fardell
Original assignee: The Boots Company Plc
Priority date: 1992-05-16
Filing date: 1993-05-12
Publication date: 1993-11-25
Also published as: GB9210517D0; AU4067193A

Abstract

The preparation of metal oxide particles having a coating of dye, said coating comprising 0.01 to 5 % by weight of the coated particle and the use of such particles in cosmetic and toiletry formulations are described.

Description

COATED PARTICLES

The present invention relates to coated particles for use in cosmetic and toiletry formulations.

The present invention provides metal oxide particles having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particle.

It has been found that cationic dyes can be used to permanently colour metal oxide particles by adsorbing directly on to the metal oxide surface. Dyes which act in this respect include those containing an iminium linkage, those containing a quaternary ammonium ion, acidic azo-dyes, pyrazole and xanthene dyes.

Dyes containing the iminium linkage of formula I:

in which R is H or a group bonded to the nitrogen atom via the carbon atom act in this respect. Examples of suitable dyes include:

FD and C Green number 3

More preferable are dyes containing a quaternary ammonium ion of formula II :

Q,^CH3

Ar-N -CH- \ IE

CH ₇

in which Ar represents an aryl group.

Examples of such dyes include:

Basic Blue 99

Basic Red 76

Basic Brown 17

Basic Brown 16

Basic Yellow 57

Such dyes exhibit particular efficacy in colouring the metal oxide particles and may be obtained commercially from Williams under the trade name Arianor.

Examples of acidic monoazo dyes suitable for coating the metal oxide particles include:

Food Yellow 5

CH-

in the form of its sodium salt; Food Red 10

in the form of its sodium salt; and

F D & C Red no. 2

S0₃Na

Examples of pyrazole dyes suitable for coating the metal oxide particles include:

F D & C Yellow no. 5

OH

Examples of xanthene dyes suitable for coating the metal oxide particles include: D & C Red no. 22

D & C Red no. 28

The metal oxide particles of the present invention preferably comprise titanium dioxide, zinc oxide or mixtures thereof. The titanium dioxide particles have a primary particle size of less than lOOnm and the zinc oxide particles have a primary particle size of 1-ess than 500nm.

One aspect of the present invention provides titanium dioxide particles having a mean primary particle size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particle. A further aspect of the^~ present invention provides zinc oxide particles having a mean primary particle size of less than 500nm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particle.

The coated metal oxide particles of the present invention may be prepared and separated as described hereinafter, or they may be prepared in situ during the preparation of emulsion products, provided that the surface of the metal oxide is hydrophilic.

To prepare the coated metal oxide particles the dye

T.S dissolved in water and metal oxide dispersed into this solution. Filtration of the resulting mixture yields highly coloured pigment which can be dried and milled to give a powder usable in cosmetic and toiletry formulations.

To prepare the coated metal oxide particles in situ, the dye is dissolved in the water phase of the formulation and the metal oxide is dispersed into the water phase of the composition during the manufacture of that composition.

In either method of preparation, the dye used may be a single dye, or a mixture of different dyes, to achieve metal oxide particles of a desired colour.

When the coated metal oxide particles are formed using certain dyes, for example Food Yellow 5, Food Red 10 or D & C Red no. 22 dye, it may be preferable to decrease the solution pH by addition of a suitable acid, such as hydrochloric acid, in order to obtain a desirable level of colour coating on the metal oxide particles. The coated metal oxide particles may be collected, for example, by filtration. The above procedures are particularly suited to the preparation of coated titanium dioxide particles, preferably having a mean primary particle size of less than lOOnm, wherein the cationic dyes adsorb directly on to the titanium dioxide surface. An analagous procedure can be applied to zinc oxide particles preferably having a mean primary particle size in the range 1 to SOOn , wherein the cationic dyes adsorb directly on to the zinc oxide surface.

The particles of the present invention may be used to prepare cosmetic and toiletry compositions, for example, sunscreens, face powders, blush powders, eye shadow powders, lipsticks, mascaras, nail polish bases and foundation creams .

The metal oxide particles in the above compositions are preferably:

a) titanium dioxide particles having a mean primary particle size of less than lOOnm, b) zinc oxide particles having a mean primary particle size of less than 500nm, or c) mixtures thereof in a ratio of between 1:99 and 90:10 of titanium dioxide:zinc oxide, preferably of between 5:95 and 60:40.

Preferred sunscreen compositions comprise the titanium dioxide particles of the present invention.

The use of titanium dioxide as a sunscreening agent is well known. The term "sunscreen" is used herein to encompass tanning lotions, sunscreens and sunblockers which are intended for use on the body to provide protection against the sun's rays or other UV sources. The amount of titanium dioxide present in a sunscreen composition depends on the use for which the composition is intended. Amounts as low as 1% by weight may be sufficient in the so-called suntanning products which are not intended to prevent the sun's rays reaching the skin whereas the so-called sunblocks which are intended to prevent substantially all of the sun's rays reaching the skin may require levels of 15 to 20% by weight. It has been found that when the amount of titanium dioxide in the sunscreen composition exceeds about 5% by weight the composition may exhibit a blue-white pearl effect which is aesthetically unattractive and limits the amount of titanium dioxide which can be incorporated into a sunscreen composition which is acceptable to the user.

It has been found that particularly beneficial sunscreen compositions have recently become available in which the mean primary particle size of the titanium dioxide particles lies in the range 1 to lOOnm, preferably in the range 5 to 50nm and more preferably in the range 15 to 30nm. Titanium dioxide of the above mean primary particle size is referred to herein as "microfine". Suitable grades of titanium dioxide are available from Degussa under the trade designation P25, and from Tayca Corporation under the trade designation MT150W, MT600B or MT500B, and from Ke ira under the trade designation UV Titan M210.

The present invention provides a sunscreen composition comprising 0.02 to 30% by weight of titanium dioxide particles, having a mean primary particle size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles. Preferably the composition comprises 0.5 to 20%, more preferably 1 to 15% by weight of the coated titanium dioxide particles.

A further aspect of the present invention provides a sunscreen composition comprising a water-in-oil emulsion which comprises:

a) 0.02 to 30% by weight of titanium dioxide particles having a mean primary size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles, b) 5 to 70% by weight of an oil phase, c) 1 to 15% by weight of an emulsifier, and d) at least 20% by weight of an aqueous phase.

A still further aspect of the invention provides a sunscreen composition comprising an oil-in-water emulsion which comprises:

a) 0.02 to 30% by weight of titanium dioxide particles having a mean particle size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles, b) 5 to 60% by weight of an oil phase, c) 1 to 20% by weight of an emulsifier, and d) at least 35% by weight of an aqueous phase.

. Other sunscreening agents may be incorporated into the sunscreen compositions of the present invention. Examples of suitable further sunscreening agents include

a) p-aminobenzoic acids, esters and derivatives (for example, 2-ethylhexyl p-dimethylaminobenzoate, or the - octyl ester of p-aminobenzoic acid) , b) methoxycinnamate esters [for example, 2-ethylhexyl p-methoxycinnamate, 2-ethoxyethyl p-methoxycinnamate or α, β-di- (p-me hoxy-cinnamoyl) -α' - (2-ethylhexanoyl) - glycerin] , c) benzo-phenones (for example oxybenzone) , d) dibenzoyl ethanes and e) salicylate esters.

Any additional sunscreening agent is present in an amount from 0.1 to 10% by weight of the composition.

The oil phase of the sunscreen compositions of the present invention, which are water-in-oil or oil-in- water emulsions may comprise:

a) hydrocarbon oils such as paraffin or mineral oils; b) waxes such as beeswax or paraffin wax; c) natural oils such as sunflower oil, apricot kernel oil, shea butter or jojoba oil; d) silicone oils such as dimethicone, cyclomethicone or cetyldimethicone; e) fatty acid esters such as isopropyl palmitate or isopropyl myristate; f) fatty alcohols such as cetyl alcohol or stearyl alcohol; or g) mixtures thereof.

In preferred water-in-oil compositions of the present invention, the oil phase comprises 5 to 60%- by weight of the composition. In preferred oil-in-water sunscreen compositions of the present invention, the oil phase comprises 10 to 30% by weight of the composition.

The emulsifiers used may be any emulsifiers known in the art for use in water-in-oil or oil-in-water emulsions. It has been found that particularly effective water-in-oil sunscreen compositions can be prepared by using an emulsifier or mixture of emulsifiers selected from:

a) ethoxylated fatty alcohols, for example the emulsifier available commercially under the trade name Brij (ICI) ; b) ethoxylated fatty acids and their esters such as ethoxylated stearates, for example the emulsifier available commercially under the trade name Myrj (ICI); c) sorbitan esters, such as the emulsifier available commercially under the trade name Span (ICI) ; d) ethoxylated sorbitan esters, such as the emulsifier available commercially under the trade name Tween (ICI); e) ethoxylated mono-di- and tri-glycerides, for example the emulsifier available commercially under the trade name Arlatone (ICI) ; f) silicon emulsifiers such as silicone polyols, available commercially for example under the trade name Abil WS08; g) anionic emulsifiers for example cetylstearyl sulphates available under the trade name Dehydag and anionic esters of mono and diglyercides available under the trade name Grindtek; h) cationic emulsifiers for example dimethyl- distearylammonium chloride available under the trade name Genamin DSAC.

The amount of emulsifier present in the water-in- oil compositions of the present invention is preferably in the range 1 to 15%.

Particularly effective oil-in-water sunscreen compositions can be prepared by using an emulsifier or mixture of emulsifiers selected from known cosmetically acceptable emulsifiers which include:

a) fatty acid soaps such as potassium stearate, b) ethoxylated fatty alcohols, for example the emulsifier available commercially under the trade name Brij (ICI) ; c) sorbitan esters, for example the emulsifier available commercially under the trade name Span (ICI) ; d) ethoxylated sorbitan esters, for example the emulsifier available commercially under the trade name Tween (ICI) ; e) ethoxylated fatty acid esters such as ethoxylated stearates, for example the emulsifier available commercially under the trade name Myrj (ICI) ; f) ethoxylated mono-, di-, and tri-glycerides, for example the emulsifier available commercially under the trade name Arlatone (ICI) ; or g) mixtures thereof.

The amount of emulsifier present in the oil-in-water compositions of the present invention is preferably in the range 1 to 10%.

The sunscreen compositions of the present invention may additionally comprise other components which will be well known to those skilled in the art for example emollients such as isopropyl myristate or a triglyceride of a fatty acid (e.g. lauric triglyceride or capric/ caprylic triglyceride) , oisturisers such as D- panthen-ol, humectants such as glycerin or 1,3-butylene- glycol, antioxidants such as DL-A-tocopheryl-acetate or butylated hydroxytoluene, emulsion stabilising salts such as sodium chloride, sodium citrate or magnesium sulphate_/ film formers to assist spreading on the surface of the skin such as alkylated polyvinyl- pyrrolidone, preservatives such as bronopol, sodium dehydroacetate, polyhexamethylenebiguanide hydro- chloride, isothiazolone or diazolidinylurea, perfumes and colouring.

It will be appreciated that the present invention includes sunscreen compositions comprising coloured titanium dioxide particles, coloured zinc oxide particles, and mixtures thereof. Compositions containing mixtures of titanium dioxide and zinc oxide particles which have not been coloured as described herein are described in British Patent Specification 2,184,356 and European Patent Application 433086.

The sunscreen compositions of the present invention described hereinbefore provide adequate protection against both UVA and UVB radiation in a composition which is aesthetically pleasing to the user, thus overcoming the problem of a blue-white tint visible on the skin after application of sunscreens containing titanium dioxide which has not been coloured in this way. Preferred sunscreen compositions are substantially transparent when applied to the skin.

A further aspect of the present invention is the use of the coated titanium dioxide particles and/or the coated zinc oxide particles described hereinbefore in cosmetic applications such as face powders, blush powders, eyeshadow powders, lipsticks, mascara, nail polish and foundation creams. The advantage -conferred by colouring such products with the said coated particles is to impart protection from the sun's rays or other UV sources when the products are applied to the body, without detracting from the aesthetic effect of the cosmetics. A further advantage conferred by colouring such products with the said coated particles is the achievement, on application of the product to the body, of a substantially transparent colour which is preferable in 'natural look' type cosmetics.

It is preferable to use prepared coated titanium dioxide particles for these formulations rather than preparing them in situ. Each cosmetic and toiletry composition may additionally comprise any other cosmetically approved colourant.

Other sunscreening agents may be incorporated into each cosmetic and toiletry composition of the present invention. Examples of suitable further sunscreening agents include:

a) p-aminobenzoic acids, esters and derivatives (for example, 2-ethylhexyl p-dimethylaminobenzoate, or the octyl ester of p-aminobenzoic acid) , b) methoxycinnamate esters (for example, 2-ethylhexyl p-methoxycinnamate, 2-ethoxyethyl p-methoxy¬ cinnamate or α,β-di-(p-methoxy-cinnamoyl) -α'- (2- ethylhexanoyl)glycerin) , c) benzo-phenones (for example, oxybenzone) , d) dibenzoylmethanes, and e) salicylate esters .

A further aspect of the present invention provides a cosmetic or toiletry composition comprising 0.05 to 25% by weight of the coated particles of the present invention together with a cosmetically acceptable diluent or carrier. The cosmetic or toiletry composition may be: a) a face powder composition comprising 0.1 to 15% by weight of the metal oxide particles,

b) a blush powder composition comprising 0.5 to 15% by weight of the metal oxide particles,

c) an eyeshadow powder composition comprising 0.5 to 15% by weight of the metal oxide particles,

d) a pearly lipstick composition comprising 0.5 to 6% by weight of the metal oxide particles,

e) a non-pearly lipstick composition comprising 2 to 8% by weight of the metal oxide particles,

f) a mascara composition comprising 0.5 to 15% by weight of the metal oxide particles,

g) a nail polish base composition comprising 0.2 to 5% by weight of the metal oxide particles,

h) a foundation cream composition comprising 0.5 to 25% by weight of the metal oxide particles.

The metal oxide particles in the above compositions may be :

a) titanium dioxide particles having a mean primary particle size of less than lOOnm, b) zinc oxide particles having a mean primary particle size of less than 500nm, or c) mixtures thereof in a ratio between 1:99 and 90:10 of titanium dioxide:zinc oxide, more preferably of between 5:95 and 60:40. The compositions of the present invention may additionally comprise other components which will be well known to those skilled in the art.

The invention will now be illustrated by the following non-limiting Examples, which are given by way of example only.

Example 1

An example of a sunscreen product containing jmicrofine titanium dioxide .coated with a dye is given below:

% w/w

1. Hydroxyethylcellulose (sold under the trade name Natrosol 250HHR) 0.5

2. Ethylenediaminetetraacetic acid tetra- sodium salt (sold under the trade name

Sequestrene Νa4) 0.1

3. 1,3 Butylene Glycol 5.0

4. Basic Brown 17 dye (sold under the trade name Arianor Sienna Brown) 0.025 5. Titanium Dioxide MT150W 5.0

6. Cetearyl alcohol (and) peg.23 stearate sold under the trade name Polawax) 2.5

^•7. Glyceryl Monostearate (sold under the trade name Monostearin NSE) _ 2.0 8. Triglyceride of saturated C10-C18 fatty acids (sold under the trade name Softisan 100) 1.0

9. White Soft Paraffin BP 3.0

10. Light Liquid Paraffin WOM14 3.0 11. Cetyl Alcohol ^~ 1.0

12.. Water to 100 The emulsion is prepared by dissolving components 2-4 in the water and dispersing into this components 1 and 5 whilst at 70°C. Components 6-11 are then heated together to 70-75°C, added to the water phase using a high shear mixer/homogeniser (Silverson) . After 5-10 minutes the product is stir cooled. The resultant cream is tan coloured and after application would leave a degree of whiteness less than would be expected for a product containing 5% of this grade of titanium dioxide.

Example 2

A sunscreen composition comprising the following constituents may be prepared:

% w/w

1. Hydroxyethylcellulose (sold under the trade name Natrosol 250HHR) 0.5

2. Ethylenediaminetetraacetic acid tetra- sodium salt (sold under the trade name Sequestrene Na4) 0.2

3. Ethoxylated Methyl Glucoside Sesqui- stearate sold under the trade name

Glucamate (SSE 20) 2.0

4. Methyl Glucoside Sesquistearate (sold under the trade name Glucate SS) 1.2

5. White Soft Paraffin BP 5.0 6. Light Liquid Paraffin WOM14 3.0

7. Cetyl Alcohol 3.0

8. Pentaerythrityl Tetraisostearate

(sold under the trade name Crodamol PTIS) 2.0

9. Ethylene Glycol Esters of fatty wax acids C18-36 (sold under the trade name Syncrowax ERLC) 2.0

10. Microfine Titanium Dioxide (sold under the trade name UV-Titan M210) 10.0

11. Basic Brown 17 dye (sold under the trade name Arianor Sienna Brown) 0.025

12.. 1,3 Butylene Glycol 5.0

13. Water to 100 Components 2, 11 and 12 are dissolved in the water and heated to 70°C. Components 1 and 10 are then dispersed into the water phase using a high shear mixer/homogeniser (Silverson) . The remaining raw materials are heated together to 70-75°C and then added to the water phase with further high shear mixing. After 5-10 minutes the emulsion is stir cooled. The resultant cream is tan coloured and after application would leave a degree of whiteness less than would be expected for a product containing 10% of this grade of titanium dioxide.

Example 3

A sunscreen composition comprising the following constituents may be prepared: % w/w

1. Hydroxyethylcellulose (sold under the trade name Natrosol 250HHR) 0.5

3. Ethoxylated Methyl Glucoside Sesqui- stearate sold under the trade name Glucamate (SSE 20) 2.0

4. Methyl Glucoside Sesquistearate (sold under the trade name Glucate SS) 1.2

5. White Soft Paraffin BP 5.0

6. Light Liquid Paraffin WOM14 3.0

7. Cetyl Alcohol 3.0

8. Pentaerythrityl Tetraisostearate (sold under the trade name Crodamol PTIS) 2.0

10. Microfine Titanium Dioxide (sold under the trade name UV-Ti an M210) 5.0

11. ^"Microfine zinc oxide 5.0 12. Basic Brown 17 (sold under the trade name Arianor Sienna Brown) 0.025

13. 1,3 Butylene Glycol 5.0

14. Water to 100

Components 2, 12 and 13 are dissolved in the water and heated to 70°C. Components 1, 10 and 11 are then dispersed into the water phase using a high shear mixer/homogeniser (Silverson) . The remaining raw materials are heated together to 70-75°C and then added to the water phase with further high shear mixing. After 5-10 minutes the emulsion is stir cooled. The resultant cream is tan coloured and after application would leave a degree of whiteness less than would be expected for a product containing 5% of this grade of titanium dioxide and 5% of this grade of zinc oxide.

Example 4

Coated titanium dioxide particles comprising the following constituents may be prepared:

% w/w 1. Microfine Titanium Dioxide (sold under the trade name UV-TITAN M210) 96

2. Cationic dye or combination of cationic dyes, for example FD and C Green number 3, Basic Blue 99, Basic Red 76, Basic Brown 17, Basic Brown 16, Basic Yellow 57,

Food Yellow 5, or Food Red 10 4

Component 2 is dissolved in water, and component 1 is dispersed into this solution. Filtration of the resulting mixture yields highly coloured titanium dioxide particles which are then dried and milled to a powder. -- Example 5

Coated zinc oxide particles comprising the following constituents may be prepared:

% w/w 1. Microfine Zinc Oxide (sold under the trade name UV-TITAN M210) 96

Food Yellow 5, or Food Red 10 4

Component 2 is dissolved in water, and component 1 is dispersed into this solution. Filtration of the resulting mixture yields highly coloured zinc oxide particles which are then dried and milled to a powder.

Example 6

A face powder composition comprising the following constituents may be prepared: w/w 1. Magnesium or Calcium Stearate

2. Dimethicone and/or Paraffin .

3. Coated Microfine Titanium Dioxide powder formed in a similar manner to that described in Example 4 ^' 4. Talc

Example 7

A face powder composition comprising the following constituents may be prepared:

% w/w 1. Magnesium or Calcium Stearate 3-8

2. Dimethicone and/or Paraffin 1-6 Coated Microfine zinc oxide powder formed in a similar manner to that described in Example 5 0.1-15.0

Talc to 100

Example 8

A blush powder composition comprising the following constituents may be prepared:

% w/w

1. Magnesium or Calcium Stearate 3-8 2. Titanium Dioxide Coated Mica 5-25

3. Dimethicone and/or Paraffin and/or

Isopropyl Palmitate 5-8

4. Coated Microfine Titanium Dioxide powder formed in a similar manner to that described in Example 4 0.5-15

5. Talc to 100

Example 9

A blush powder composition comprising the following constituents may be prepared: % w/w

1. Magnesium or Calcium Stearate 3-8

2. Titanium Dioxide Coated Mica 5-25

3. Dimethicone and/or Paraffin and/or

Isopropyl Palmitate 5-8 4. Coated Microfine Titanium Dioxide powder formed in a similar manner to that described in Example 4 0.25-7.5

5. Coated Microfine Zinc Oxide powder formed in a similar manner to that described in Example 5 0.25-7.5

6. Talc to 100 Example 10

An eyeshadow powder composition comprising the following constituents may be prepared:

% w/w 1. Calcium or Magnesium Stearate 4-12

2. Titanium Dioxide Coated Mica 5-60

3. Dimethicone and/or Paraffin and/or Isopropyl Palmitate 5-20

Example 11

A pearly lipstick composition comprising the following constituents may be prepared:

% w/w

1. Carnauba Wax 1.5

2. Beeswax 8

3. Ozokerite 7

4. Condensate of lanolin fatty acids with ethylene oxide (sold under the trade name Lanpol 5 Croda) 8

5. Triglycerides of capric and caprylic acids (sold under the trade name

Miglyol 812) 2 6. Castor Oil 50

7. Propylene Glycol 1.5

8. Coated Microfine Titanium Dioxide powder formed in a similar manner to that described in Example 4 0.5-6 9. Pearl 7-20

10. Mixture of fatty alcohols, chiefly oleyl - alcohol (sold under the trade name Novol Croda 18 Example 12

A non-pearly lipstick composition comprising the following constituents may be prepared:

% w/w 1. Carnauba Wax 4

2. Beeswax 4

3. Ozokerite 4

4. Cetyl Alcohol 0.6

5. A standard blend of ozokerite (sold under the trade name Okerin Wax 239) 0.8

6. Condensate of lanolin fatty acids with ethylene oxide (sold under the trade name Lanpol 5 Croda) 10

7. Mixture of fatty alcohols, chiefly oleyl alcohol (sold under the trade name Novol Croda) 23

8. Castor Oil 50

9. Coated Microfine Titanium Dioxide powder formed in a similar manner to that described in Example 4 5

Example 13

A mascara composition comprising the following constituents may be prepared:

% w/w 1. Carnauba Wax 8

2. Beeswax 8

3. A standard blend of Ozokerite (sold under the trade name Okerin Wax) 8

4. Stearic Acid 6.3 5. C11-C13 Isoparaffin (sold under the trade name Isopar) 5.0 6. Triethanolamine 5.0

7. Coated Microfine Titanium Dioxide powder formed in a similar manner to that described in Example 4 0.5-15 8 Synthetic Magnesium Aluminium Silicate

(sold under the trade name Veegum) 2.4

9. Lecithin 0.45

10. 1,3-Butylene Glycol 3

11. Film former comprising ammonium acrylates copolymer, propylene glycol and potassium octoxynol-12 phosphate and non-oxynol-10 (sold under the trade name Syntran 5170) 10

12. Water to 100%

Example 14

A nail polish base composition comprising the following constituents may be prepared:

% w/w

10 10

5

20

15 35

e Titanium Dioxide powder formed in a similar manner to that described in Example 4 0.2-5'

Example 15

A foundation cream composition comprising the following constituents may be prepared: % w/w

1. Glycerin 5

2. Xanthan Gum 0.2

3. Cetearyl alcohol (and) PEG 23 stearate (sold under the trade name

Polawax 2.5

4. Stearic Acid Toilet 0.5

5. Petrolatum 1.0

6. Cetyl Alcohol 0.7 7. Dimethicone 4.5

8. Arachidyl Propionate 2.5

9. Cocoa Butter 1.5

10. Cetearyl Octanoate 1.5

11. Mineral Oil 5 12. Potassium Hydroxide 0.07

13. Powdered Nylon 1

14. Colour Paste (comprising coated Microfine Titanium Dioxide powder, formed in a similar manner to that described in Example 4, 50%, in

1,3-butylene glycol, 50%) 0.5-25

15 Water to 100

Example 16

A foundation cream composition comprising the following constituents may be prepared:

% w/w

1. Glycerin 5

2. Xanthan Gum 0.2

3. Cetearyl alcohol (and) PEG 23 stearate (sold under the trade name

Polawax 2.5 4. Stearic Acid Toilet 0.5

5. Petrolatum 1.0

6. Cetyl Alcohol 0.7 . Dimethicone 4.5 8. Arachidyl Propionate 2.5

9. Cocoa Butter 1.5

10. Cetearyl Octanoate 1.5

11. Mineral Oil 5

12. Potassium Hydroxide 0.07 13. Powdered Nylon 1

14. Colour Paste (comprising coated Microfine Zinc Oxide powder, formed in a similar manner to that described in Example 5, 50%, in 1,3-butylene glycol, 50%). 0.5-25

15. Water to 100%

Claims

1. Metal oxide particles having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles.

2. Titanium dioxide particles having a mean primary particle size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles.

3. Zinc oxide particles having a mean primary particle size of less than 500nm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles.

4. A combination of titanium dioxide particles having a mean primary particle size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles, and zinc oxide particles having a mean primary particle size of less than 500nm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles, in a ratio of between 1:99 and 90:10.

5. A sunscreen composition comprising 0.02 to 30% by weight of coated metal oxide particles as claimed in claim 1.

6. A sunscreen composition comprising 0.02 to 30% by weight of coated titanium dioxide particles as claimed in claim 2.

7. A sunscreen composition comprising 0.02 to 30% by weight of coated zinc oxide particles as claimed in claim 3.

8. A sunscreen composition as claimed in Claim 6 comprising a water-in-oil emulsion which comprises: a) 0.02 to 30% by weight of titanium dioxide particles having a mean primary size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles, b) 5 to 70% by weight of an oil phase, c) 1 to 15% by weight of an emulsifier, and d) at least 20% by weight of an aqueous phase.

9. A sunscreen composition as claimed in Claim 6 comprising an oil-in-water emulsion which comprises: a) 0.02 to 30% by weight of titanium dioxide particles having a mean primary particle size of less than lOOnm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles, b) 5 to 60% by weight of an oil phase, c) 1 to 20% by weight of an emulsifier, and d) at least 35% by weight of an aqueous phase.

10. A sunscreen composition as claimed in any one of claims 6, 8 or 9 additionally containing zinc oxide particles having a mean primary particle size of less then 500nm and having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particles.

11. A cosmetic or toiletry composition comprising 0.05 to 25% by weight of metal oxide particles as claimed in claim 1 together with a cosmetically acceptable diluent or carrier.

12. A cosmetic or toiletry composition as claimed in claim 11 which is: a) a face powder composition comprising 0.1 to 15.0% by weight of the metal oxide particles,

b) a blush powder composition comprising 0.05 to 15% by weight of the metal oxide particles,

c) an eye-shadow powder composition comprising 0.5 to 15% by weight of the metal oxide particles,

g) a nail polish base composition comprising 0.2 to 5% by weight of the metal oxide particles, or

13. A cosmetic or toiletry composition as claimed in claim 11 or claim 12 in which the metal oxide particles are:

a) titanium dioxide particles having a mean primary particle size of less than lOOnm, b) zinc oxide particles having a mean primary particle size of less than 500nm, or c) mixtures thereof in a ratio between 1:99 and 90:10 of titanium dioxide:zinc oxide, more preferably of between 5:95 and 60:40.

14. A process for the preparation of metal oxide particles having a coating of dye, said coating comprising 0.01 to 5% by weight of the coated particle, comprising dissolving the dye in water and dispersing metal oxide particles into the solution, the coated particles being collected by filtration.

15. A process for the preparation of metal oxide particles having a coating of dye, said coating comprisisng 0.01 to 5% by weight of the coated particle, during the preparation of emulsion products comprising dissolving the dye in the water phase and then dispersing the metal oxide into the water phase.