GB2382350A

GB2382350A - Soluble sachet containing effervescent base material

Info

Publication number: GB2382350A
Application number: GB0221861A
Authority: GB
Inventors: Alison Cowan; Graham Robert Horne; Craig Joseph Davies; Jason Ronald Fullman
Original assignee: PZ Cusons PLC
Current assignee: PZ Cusons PLC
Priority date: 2001-09-20
Filing date: 2002-09-20
Publication date: 2003-05-28
Also published as: GB0122665D0; US20030080150A1; GB0221861D0

Abstract

A sachet formed from a water soluble plastics material comprises a personal care composition, which includes at least one surfactant together with an effervescent base material, wherein the base material liberates a gas when in contact with a sufficient amount of water. Typically, the base material comprises a carbonate and/or a bicarbonate, e.g. sodium bicarbonate in combination with an acid, such as citric acid. The base material and the surfactant(s) may be provided in powdered or granular form. The surfactant(s) may be anionic, nonionic, cationic, amphoteric or mixtures thereof The plastics material may be polyvinyl alcohol, polyvinyl pyrrolidine, a starch-based polymer, cellulose, or an alginate. The sachet is preferably for addition to bath water.

Description

1 2382350

DISPENSER FOR PERSONAL CARE COMPOSITION

The present invention relates to a dispenser containing a personal care composition and particularly, but not exclusively, to a dispenser containing such compositions as are generally added to a bath.

5 Many types of personal care products are available for use in the bath. Some deliver additives to the bath, such as minerals, emollients, colour, fragrance, skin conditioning agents and so forth. Others are designed to deliver lather to the bath.

Whilst this may be achieved through the incorporation of a suitable surfactant into the formulation many of these products, particularly those with high surfactant levels, 10 require a large degree of hand agitation to aid their dissolution. As a result of this foam does not form in any great amount until some time after the product has been added. More recently effervescent bath tablets have been marketed. One composition of this type is described in US 6121215. AnLydrous solid systems of this type generally comprise a combination of carbonate/bicarbonate salts, typically sodium 15 bicarbonate, with acids, typically citric acid, which on contact with water react to release carbon dioxide. The function of these products is primarily the delivery of fragrance and/or colour to the bath water.

For bath applications these solid systems, often known as bath tablets and bath bombs, are compressed under high pressure into tablets or spheres. Additives have 20 been added to these systems, typically colour, fragrance and oils. Surfactants have occasionally been added to these systems but at low levels to help bind these systems together and at such low levels no foam is produced.

Whilst it would seem that the inclusion of a higher level of surfactants in these systems would deliver a suitably foaming effervescent bath product this is not actually

the case. As the level of surfactant is increased in these systems the speed of the effervescent reaction and hence dissolution is dramatically reduced giving a product which neither effervesces nor foams particularly effectively. It is a further observation that the pressure of binding involved in these systems also affects the 5 speed of dissolution and effervescence and hence foaming. As the tableting pressure is increased, these systems dissolve more slowly and effervesce and foam less readily.

U.S. Patent No. 6,121,215 discloses that for high dissolution and good foaming performance an effervescent foaming product should be designed to have a low density. This is achieved by using a moulding process rather than tableting the 10 materials under pressure. However, the speed of dissolution and hence foaming from such a system, whilst improved over the standard tablet pressure method of formation, is not particularly rapid. In addition these systems tend to leave undissolved residual material in the bath. This is a major disadvantage of currently marketed bath tablets and bombs in that this is not acceptable to the consumer.

15 It is known to provide laundry formulations in a water soluble sachet. Such compositions do contain surfactants and so would generate some foam if used in a bath, but would have several disadvantages should they be so employed. Laundry formulations are specifically designed to give a controlled quantity of foam tailored to the wash habit and method of washing. With front loading washing machines a low 20 degree of foam is required due to the mechanical action of the wash process. A common practice is to control or restrict foam generation using anti-foaming agents such as silicone compounds. For top-loading washing machines or hand-washing applications higher foam level is required for aesthetic reasons. However, foam control is still necessary to ensure ease in rinsing garments after the washing process.

In general the level of foam and foam stability is significantly lower than that required for bath applications.

In addition many of the additives included in these formulations, such as enzymes and bleach, are skin irritants which clearly are not suitable in bath 5 forrnuIations. The surfactants used in laundry applications are harsh and would not be suitable for bath applications as they would be likely to irritate the skin. Similarly, the pH produced by laundry powder systems on dissolution into water is much higher (typically >10) than would be acceptable for a personal cleansing application.

In any event disintegration and dissolution of such sachets in laundry 10 applications relies heavily upon the significant mechanical energy produced in a washing machine during the washing cycle. Consequently such a sachet comprising a laundry composition would be unsuitable for use in the bath.

The present invention has been made from a consideration of this.

According to the present invention there is provided a dispenser, in the form of 15 a sachet made from a water-solubló plastics material, containing a personal care composition comprising at least one surfactant together with an effervescent base material, said base material comprising any material or combination of materials that when in contact with a sufficient amount of water liberates gas.

In use the sachet quickly dissolves under running water and the formulation 20 inside reacts, quickly dissolves and rapidly produces copious amounts of foam overcoming the poor dissolution properties experienced currently with some conventional bath liquids.

The dispenser of the invention provides an aesthetically pleasing foaming bath product provided in a single-shot ready-dosed easy-to-handle form. The presence of

the effervescent base material provides for the quick disintegration of the sachet and also gives greater dispersion of the sachet contents once released.

Preferably on dissolving the water-soluble sachet does not act as a skin irritant. The sachet preferably comprises any water-soluble film, ideally comprising 5 any of the following materials either along or in combination: poly-vinyl alcohol (PVOH) polymer, poly-vinyl pyrolidene (PVP) polymer, starch-based polymer or natural substances such as rice paper, cellulose and alginates. The preferred film thickness is dependent on the solubility characteristics of the film material. For the preferred film material, PVOH, the preferred film thickness would be 10 -1000 1lm.

10 preferably 15 - 80 1lm and most preferably 20 - 60 m. The sachets can be formed by one or more continuous pieces of film that are sealed longitudinally and/or transversely at appropriate places to form a sachet by either heat sealing or adhesive sealing. The sachet allows accurate dosing for one-shot delivery and also allows the effervescent base material and the surfactant to be held in GlOSe proximity without the 15 need for moulding or tableting of ingredients that would reduce solubility and performance. The effervescent base material and surfactant are ideally combined together in powdered or granular form and then filled into the sachet. Alternatively the individual components of the sachet could be added separately or in a variety of 20 combinations of individual components. The contents of the sachet are substantially anhydrous. The surfactant or surfactant systems may be chosen from any of the anionic, non-ionic, cationic or amphoteric classes of surfactants that are suitable for personal care use. Examples of anionic surfactants include salts of fatty acids (e.g. Sodium

laurate), alkyl sulphates (e.g. Sodium lauryl sulphate), alkyl ether sulphates (e.g. Sodium lauryl ether sulphate), aromatic hydrocarbon sulphonates (e.g. Sodium cumene sulphonate), isethionates (e.g. Sodium cocyl isethionate), and sulphosuccinates (e.g. Sodium lauryl sulphosuccinate). Examples of amphoteric 5 surfactants include, alkyl amphoacetates (e.g. cocoamphoacetate), betaines (cocamidopropyl betaine) and amphopropionates (e.g. Sodium cocoamphopropionate). Examples of nonionic surfactants include fatty alcohol ethoxylates (e.g. Iaureth-4), fatty acid alkanolamides (e.g. cocamide DEA), amine oxides (e.g. alkyl dimethyl amine oxide) and alkyl polyglucosides (e.g. Iauryl 10 glucoside). Examples of a cationic surfactant are the quaternary ammonium compounds (e.g. alkyl trirnethyl ammonium chlonde). Mixtures of the above surfactants can also be used. The surfactant is necessary to provide foam as well as for cleaning purposes. In a prefesred embodiment, the surfactant level would typically comprise between 1-999to of the total composition, preferably 2.5-60% and 15 most preferably 5-30% w/w.

Tbe effervescent base ideally produces carbon dioxide gas on contact with a sufficient amount of water. In a preferred embodiment, the base material would typically comprise between 1-99% of the total composition, preferably 40-97.5% and most preferably 70-95% w/w. The effervescent base ideally comprises one or more 20 alkaline carbonate andlor bicarbonate salt in combination with at least one acid.

Typically these would be added in stoichiometric amounts so that a complete reaction occurred although it may be preferred to add one or the other material in excess.

Examples of alkaline carbonate and bicarbonate materials include sodium bicarbonate, potassium bicarbonate, sodium, carbonate, potassium carbonate, sodium

sesquicarbonate, potassium sesquicarbonate, calcium carbonate, magnesium carbonate, ammoniurn carbonate, ammonium bicarbonate and ammonium sesquicarbonate. Examples of suitable acids include citric acid, formic acid, tartaric acid, glycolic acid, salicylic acid, sorbic acid, maleic acid and lactic acid. A preferred 5 embodiment of the effervescent base material would include sodium bicarbonate and citric acid.

The composition may additionally comprise further ingredients as are conventionally used in bath products such as any of the following either alone or in combination:- colourants, preservatives, fragrance, skin conditioning agents or anti 10 bacterial agents.

Colourants would be chosen from those known to cosmetic chemists. Typical colourants include Fl)&C certified colours in the US and those given CI numbers in the KU. Such materials would be included at a level designed to impart either the formulation and/or the bath water with an aesthetically pleasing colour and would be 15 selected to be compatible with the other ingredients in the base. Colourants would be typically included at between 0.01% to 5% of the weight of the total composition.

Preservatives can be chosen from those commonly known to cosmetic chemists and would be included at levels that would effectively prevent microbial contamination in the product. Typical preservative materials include phenoxyethanol, 20 methylparaben, butylparaben, isobutylparaben, ethylparaben, propylparaben, isopropylparaben, diazolidinyl urea, imidazolidinyl urea and benzyl alcohol.

Preservatives would be typically included at between 0.01% and 2 o of the weight of the total composition.

Fragrances are mixtures of odoriferous components and would be chosen to provide the formulation with a pleasing odour. Typical levels of fragrance would be O.l o to To of the weight of the total composition, Anti-bacterial agents are components that are used to reduce the number of 5 germs of the surface of the skin. Typical antibacterial ingredients include, 2,4,4'-

trichloro-2'-hydroxy-diphenyl ether (more commonly referred to as Triclosan or TCS), 3,4,4'-trichlorocarbanilides (more commonly referred to as Triclocarban or TCC) and para-chloro-meta-xylene (PCMX). Typical levels of the anti-bacterial agent would be 0.001% to 5% of the weight of the total composition.

10 The composition may additionally comprise further ingredients that aid the flow of powder within the sachet. Typical flow agents include starch, silica and talc.

Typically these ingredients are included at between 0.1 & 10 o of the total weight of the composition.

As this invention concerns materials which will react on contact with water is 15 important that the levels of water in the composite ingredients is minimised. It is preferable that only very low levels of water are contained in the formulation and that any water which is found within the formulation is bound chemically or physically to prevent sachet dissolution and/or the effervescent base to begin to react.

In order that the present invention may be more readily understood a specific 20 example will now be described by way of example only with reference to the accompanying examples.

Example

Weigh out ingredients as listed below. Mill ingredients together until homogenous. Fill into PVOH sachet:

INGREDIENTS %w/w Sodium Bicarbonate 46.5480% Citric Acid 38.8210% Sodium Lauryl Sulphate 11.5000% Cocamidopropyl Betaine 2.1000% _ Fragrance q.s.

_ Colour q.s.

It is to be understood that the above described example is by way of illustration only. Many modifications and variations are possible.

Claims

1. A dispenser, in the form of a sachet, made from a water-soluble plastics material, containing a personal care composition comprising at least one surfactant together with an effervescent base material, said base material comprising any S material or combination of materials that when in contact with a sufficient amount of water liberates gas.

2. A dispenser according to claim 1, wherein the sachet is made from a water-

soluble film.

3. A dispenser according to any preceding claim, wherein the said sachet is made 10 from any of the following materials either alone or in Combination:- poly-vinyl alcohol (PVOH) polymer, poly-vinyl pyrrolidine (PVP) polymer, starch-based polymer, cellulose and alginates.

4. A dispenser according to claim 3, wherein the said sachet comprises a poly-

vinyl alcohol film having a thickness of 10 to 1000pm.

15 S. A dispenser according to claim 4, wherein the said sachet has film thickness of 15 to 801lm.

6. A dispenser according to claim 4, wherein the said sachet has a film thickness of 20 to 601lm.

7. A dispenser according to any preceding claim, wherein the said effervescent 20 base material and surfactant are combined together in a powdered or granular form.

8. A dispenser according to any preceding claim, wherein the sachet contains a personal care composition in which the components are anhydrous.

9. A dispenser according to any preceding claim, wherein the said at least one surfactant comprises any of the following either alone or in combination:- anionic, non-anionic, cationic or amphoteric surfactant.

10. A dispenser according to any preceding claim, wherein the surfactant 5 comprises at least one anionic surfactant selected from any of the following either alone or in combination:- salts of fatty acids, alkyl sulphates, aLkyl ether sulphates, aromatic hydrocarbon sulphate, isethionates and sulphosuccinates.

11. A dispenser according to any preceding claim, wherein the surfactant comprises at least one amphoteric surfactant selected from any of the following either 10 alone or in combination:- alkyl arnphoacetates, betaines and amphopropionates.

12. A dispenser according to any preceding claim, wherein the surfactant comprises at least one non-ionic surfactant selected from any of the following either alone or in combination:- fatty alcohol ethoxyltes, fatty acid alkanolamides, amine oxides and aLkyl polyglucosides.

15 13. A dispenser according to any preceding claim, wherein the surfactant comprises a quaternary ammonium compound.

14. A dispenser according to any preceding claim, wherein the said at least one surfactant constituters from 1% to 99%, by weight, of the total composition.

15. A dispenser according to claim 14, wherein the said at least one surfactant 20 constitutes from 2.5% to 60%, by weight, of the total composition.

16. A dispenser according to claim 14, wherein the said at least one surfactant constitutes from 5% to 30%, by weight, of the total composition.

17. A dispenser according to any preceding claim, wherein the said effervescent base material constitutes from 1% to 99%, by weight, of the total composition.

11.' 18. A dispenser according to claim 17, wherein the said effervescent base material constitutes from 40 o to 97.5%, by weight, of the total composition.

19. A dispenser according to claim 17, wherein the said effervescent base material constitutes from 70% to 95%, by weight, of the total composition.

5 20. A dispenser according to any preceding claim, wherein the said effervescent base material comprises at least one alkaline carbonate and/or bicarbonate salt in combination with at least one acid.

21. A dispenser according to claim 20, wherein the said alkaline carbonate andlor bicarbonate materials comprise any of the following either alone or in combination: 10 sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium sesquicarbonate, potassium sesquicarbonate, calcium carbonate, magnesium carbonate, ammonium carbonate, ammonium bicarbonate and ammonium sesquicarbonate. 22. A dispenser according to claim 20, wherein the said acid comprises any of the 15 following either alone or in combination:- citric acid, formic acid, tartaric acid, glycolic acid, salicylic acid, sorbic acid, maleic acid and lactic acid.

2. A dispenser according to any preceding claim, wherein the said personal care composition comprises a stoichiometric amount of said effervescent base material.

24. A dispenser according to any preceding claim, wherein the said effervescent 20 base material comprises sodium bicarbonate and citric acid.

25. A dispenser as hereinbefore described with reference to the example.