WO2005030383A1

WO2005030383A1 - Encapsulated products

Info

Publication number: WO2005030383A1
Application number: PCT/GB2004/003837
Authority: WO
Inventors: Malcolm Tom Mckechnie
Original assignee: Reckitt Benckiser (Uk) Limited
Priority date: 2003-09-25
Filing date: 2004-09-08
Publication date: 2005-04-07
Also published as: GB0322467D0

Abstract

The present invention provides a product comprising a pressurised container, wherein said container comprises therein a microbial encapsulating material, and a propellant, a method of cleaning a substrate using said pressurised containers, and a process for the preparation of said pressurised containers.

Description

ENCAPSULATED PRODUCTS

The present invention relates to micro-encapsulation, i.e. the encapsulation of materials in microbial cell capsules, and to materials produced by microbial encapsulation.

It is well-known that it is possible to encapsulate various substances in naturally-occurring microcapsules (alternatively known as biocapsules) . Previous studies have shown that it is possible to bioencapsulate in such organisms as yeast cells, microfungi, bacteria, and algae, see US-A-4696863, GB-A-2162147 , and EP-A-0242135.

EP-A-0085805 discloses the treatment of fungi with organic liquid lipid-extending substances and with materials which are soluble or microdispersible in those substances so that both the lipid-extending substance and the material which is soluble or microdispersible therein enter and are retained within the fungi. Similar disclosures are made in GB-A-2162147 wherein the fungi have a much lower microbial lipid content than those in EP-A-0085805.

FR-A-2179528 describes a method wherein certain materials are absorbed and/or fixed by microbes, in which the microbe, such as pressed industrial yeast, is treated with a plasmolyser, and then an aqueous solution of a material is added under certain conditions so that the aqueous material is absorbed in place of the cytoplasmic fluid that is extracted from the microbe by the plasmolyser.

EP-A-0242135 avoids the requirement to use a microbe with a high l±pid content or a lipid-extending substance or plasmolyser by contiguously mixing the microbe with ' the encapsulated material liquid in the presence of an aqueous medium to produce an aqueous emulsion.

GB-A-2234901 discloses a method of encapsulating a water- insoluble substance within a carrier, such as starch, wherein the carrier is suspended in a modifying agent and the water-insoluble substance is then dissolved therein. The modifying agent modifies the carrier such that it imbibes the water-insoluble substance. One example of the modifying agent is anhydrous liquid ammonia.

EP-A-0691885 addresses the problems involved with, the encapsulation of a water-soluble substance in yeast cells, particularly when the substance is likely to pass out of the encapsulating material as easily as the substance is passed in. The method disclosed involves dissolving the substance in liquid ammonia, passing the solution formed into the yeast cell and then removing the liquid ammonia such that the substance remains encapsulated in the yeast cell.

Conventional aerosol products fall into one of several main classes; these include those where an effective ingredient is discharged in the form of a mist, e.g. hair sprays and the like, those where the ingredient is ejected as a foam, e.g. shaving creams and the like, and dry powder spray aerosols, e.g. talc-type sprays. It is desirable to provide a wide range of products in foam form, including skin and oral cleansers, shampoos, household cleaners, household waxes, cosmetics, and. the like . Previously, it has been found desirable that foaming products be capable of producing auditory or continued bubbling effects for a time long after the discharge or ejection of the product from the pressurised aerosol container. Such prolonged auditory effects can act as an indicator of both the presence and continued action of the particular product. Moreover, the effects can be a way of prolonging the action of the product over time.

Previously, the length of time of the prolonged auditory effect has been of very short duration, and hence the beneficial effects of prolonged bubbling have been limited. In order to maintain the beneficial effects over a substantial period of time, several methods have been disclosed.

In US-A-4574052, an aerosol composition is disclosed containing zeolite, surfactant and propellant. However, it is known that zeolite particles impart a sandy, gritty feeling. In EP-A-0376104, the problem is addressed by the introduction of a large proportion of propellant, from 10- 90% by wt of the concentrate.

Therefore, there remains the need to find products suitable for ejection or discharge from a pressurised container and which address and alleviate the problems highlighted above, particularly with respect to encapsulation of active ingredients in microbial environments and the production of foaming products with useful characteristics, for example with respect to user convenience and general effectiveness. It is an object of the present invention to provide a novel aerosol composition. A further object is to provide a novel aerosol composition with improved long-term properties, for instance, with respect to the lifetime of a foam produced and its characteristics, and hence, improved properties in-use. A yet further object is to provide a novel aerosol composition which forms a foam with improved ^λcrackling' or bubbling' characteristics.

A still yet further object is to provide a novel aerosol composition which is able to distinguish oily and oil- based stains or regions from non-oil-based stains or regions, for example by providing an aerosol composition with enhanced foam generation properties on hydrophobic regions compared to hydrophilic regions. Additionally, the novel aerosol composition may exhibit enhanced cleaning performance in the hydrophobic regions, these regions tending conventionally to present the most problems during the cleaning process. A still further object is to provide a novel product comprising a pressurised container comprising therein a novel composition as set out hereinbefore.

According to the present invention, there is provided a novel product as set forth in the appended claims . Preferred features of the invention will be apparent from the dependent claims, and the description which follows.

Thus, according to a first aspect, the present invention provides a product comprising a pressurised container, wherein said container comprises therein a microbial encapsulating material, and a propellant. Preferably, the said pressurised container further comprises at least one active agent.

Preferably, the propellant is present as an aqueous solution thereof or as part of an emulsion or two-phase system or non-aqueous solution, for example with a non- water vehicle.

It has surprisingly been found that the introduction into a pressurised container of a microbial encapsulating material, together with at least one propellant and, preferably, at least one active agent, provides a product which upon discharge/ejection from said container, has improved properties over similar mixtures within such containers but not including the microbial encapsulating material .

Suitably, the release of the propellant from the microbial encapsulating material will be attenuated to some degree by the encapsulation of at least a proportion of the propellant within the encapsulating material and furthermore, the release of the propellant will be promoted when the microbial encapsulating material and propellant are in contact with certain materials which promote such release compared to when they are not in contact with such materials. Materials which satisfy this requirement include, in addition to hydrophobic materials, surfactant solutions, mucous membranes, and microbial surfaces .

Suitably, the invention relates to the slow and area- specific delivery of the propellant. As such, the delivered propellant can be chosen to have desired properties, for example cleaning properties. Moreover, the additional presence of an active agent, preferably dissolved in the propellant and therefore encapsulated, at least to some extent, in the encapsulating material, can lead to a product wherein the active agent is delivered slowly, and in an area-specific manner, to a surface or the like.

By "pressurised container", we mean a vessel, the contents of which are kept at pressures above normal atmospheric pressure, for example at pressures of 3 bar, preferably at between 2 bar and 12 bar, and from which the contents can be discharged/ejected by some action of the user.

By "microbial encapsulating material", we mean any microbial material capable of encapsulating materials, such as, in the present invention, said propellant or said propellant and said active agent.

By "active agent" or "active ingredient", we mean any entity which assists the particular function of the product and which is not the propellant.

Suitably, said microbial encapsulating material is a fungus. Preferably, said fungus is yeast. Suitable yeasts include brewer's and baker's yeast ( Saccharomyces cerevisiae) , dairy yeast (Kluyveromyces fragilis) and Candida utilis . Alternatively, bacteria and algae may be employed as the microbial encapsulating material.

Encapsulation of the propellant and the active agent can be performed by any of the methods known in the art . For example, any of the methods disclosed in US-A-4696863, GB- A-2162147, EP-A-0242135, EP-A-0085805, EP-A-511258, FR-A- 2179528, GB-A-2234901 and EP-A-0691885, the disclosures of which are herein incorporated by reference, can be used for the encapsulation.

Nevertheless, in order to encapsulate the aqueous or non- aqueous solution of the propellant, and the active agent in the preferred embodiments, the following method can be employed; the microbial encapsulating material and water (when present) or vehicle can simply be mixed with the propellant and active agent (when present) and pressurised within a suitable container, such as an aerosol or production container. Preferably, the temperature is maintained at ambient room temperature, or between 40°C and 80°C for between 1 and 24 hours, preferably between 2 and 4 hours. In the latter case, the temperature is then dropped and the propellant/active agent is/are encapsulated .

Preferably, the propellant comprises one or more aliphatic hydrocarbons, one or more fluorinated hydrocarbons, or mixtures thereof.

Suitable fluorinated hydrocarbons are selected from the list comprising octafluorocyclobutane (FREON C-318), monochloropentafluoroethane (FREON-115) , chlorodifluoro ethane (FREON-22), dichlorodifluoromethane (FREON-12), l,2-dichloro-l,l,2,2-tetrafluoroethane (FREON- 114), and dichloromonofluoromethane (FREON 21), preferably non-ozone-depleting fluorinated hydrocarbons, such as difluoroethane (HFC 152a) , and tetrafluoroethane (HFC 134) . Suitable aliphatic hydrocarbons are selected from the list comprising propane, butane, isobutane, cyclobutane and pentane, and mixtures thereof, and the like.

Alternatively, the propellant may comprise ethers, for example dimethylether, nitrogen, or air, or mixtures thereof.

Preferably, the propellant comprises butane, more preferably n-butane. Most preferably, the propellant comprises a mixture of n-butane and pentane, preferably n- pentane, more preferably i-pentane; this mixture will not harm the environment and produces a crackling foam when the composition is delivered from a pressurised container .

Without wishing to be bound by theory, it is believed that both the propellant and the active agent (when present) are encapsulated at least to some degree by the microbial material within the pressurized container. When the product is released from the container the rate at which the propellant and active ingredient are released from th.e microbial material environment is determined by the nature of the substrate onto which the product is released. Alternatively, it is possible that solely the propellant is encapsulated by the microbial material, even when an active agent is also present. In this case, the active agent remains external to the encapsulating material. A.s a further alternative, the active agent may be present somewhere between these two extremes, i.e. not fully- encapsulated nor fully non-encapsulated, but encapsulated to a certain degree. In all cases, the propellant must be encapsulated within the encapsulating material, at least to some degree. Preferably, at least 1% of the propellant should be encapsulated, more preferably 10% of the propellant, even more preferably at least 20% of the propellant, yet more preferably at least 40% of the propellant, yet even more preferably at least 60% of the propellant, most preferably at least 80% of the propellant is encapsulated.

Moreover, the active agent, when present and when encapsulated, is encapsulated such that at least 1% of the active agent is encapsulated, more preferably 10% of the active agent, even more preferably at least 20% of the active agent is encapsulated, yet more preferably at least 40% of the active agent, yet even more preferably at least 60% of the active agent, most preferably at least 80% of the active agent is encapsulated.

If the substrate is hydrophilic in nature, the encapsulated material is released only very slowly; on the other hand, if the substrate is hydrophobic in nature, the encapsulated material is released at a much quicker rate.

Nevertheless, the fact that the encapsulated material is encapsulated at all will ensure that the material is released at a slower rate than would be the case if the microbial encapsulating material were not present and the propellant/active material were simply released from the pressurised container, even on hydrophobic surfaces.

Thus, one advantage of the present invention is to delay the release of the propellant/active ingredient compared to the case where no encapsulating material is present, thus ensuring a longer lasting foam product to be released. As such, the release of the propellant and active ingredient is delayed compared to the case where no encapsulating material is present.

A still further advantage of the present invention arises from the fact that the rate at which the propellant and active ingredient are released from the microbial material environment is determined by the hydrophilic/hydrophobic nature of the substrate onto which the product is released. In a hydrophilic environment, encapsulated material is released slowly; in a hydrophobic environment, release is relatively quick. Hence, a vigorous but fairly long-lasting foam results on a hydrophobic substrate, with, only a weak foam, if at all, being present on a hydrophilic substrate.

Suitably, the product of the present invention is a cleaning product, preferably a household cleaning product, but also the product can be a non-household cleaning- product, for example when used in the preparation off surfaces for painting, or de-contaminating surfaces in the food industry sector, and the like. Such products include, but are not limited to, household hard surface cleaners, and by "hard surface", we include glass, ceramic, metal, wood and plastic surfaces. As such, the active agent in this embodiment of the invention will be selected from those active agents which can function as hard surface cleaners, for example surfactants or solvents, optionally abrasive agents, which are conventionally known in the art of hard surface cleaners. Alternatively, the propellant itself may act as a hard surface cleaner. Moreover, the hard surface cleaner can additionally possess an antimicrobial and/or disinfectant active agent, for example, the quaternary surfactant-based agent para-chloro meta xylenol (PCMX) , and/or an antifungal agent.

Alternatively, the product of the present invention may be a polish and used for polishing surfaces including floors, furniture, shoes or metals. In such embodiments, the active ingredient is one that exhibits a polishing effect on a surface, for example, silicones or waxes.

Equally, the product of the present invention may be an insecticide or an insect repellent, particularly one for domestic use. In such embodiments, the active ingredient is one that exhibits an insecticidal or insect repellent effect, for example, pyrithrides or citronella.

Suitably, the product of the pre sent invention is an air care product. By "air care product", we include malodour neutralisers, fragrances, and anti-allergenic agents delivered in air spaces, preferably household air spaces. As such, the active agent in this embodiment of the invention will be selected from those active agents which can function as malodour neutralisers, fragrances, and/or anti-allergenic agents, particularly in the household environment, for example alde iydes can function as malodour neutralisers, and pyrethiides, and benzylbenzoate can act as anti-allergenic agents. Moreover, the active agent in this embodiment can function as an allergen neutraliser and details of such neutralisers can be found in WO-A-99/15208 and WO-A-01/76371, the contents of both of which are herein incorporated by reference.

Suitably, the product of the present invention is an automatic dishwashing detergent. Such products include, but are not limited to, detergents which are placed "in the machine" during the wash cycle, and those used as either pre- or post-wash treatments. As such, the active agent in this embodiment of the invention is selected from those active agents which function as automatic dishwashing detergents, for example surfactants, for example anionic, cationic, amphoteric or zwitterionic surfactants, or enzymes.

Suitably, the product of the present invention is a carpet cleaner. As such, the active agent in this embodiment of the invention will be selected from those active agents which can function as carpet cleaners, for example surfactants, for example anionic, cationic, amphoteric or zwitterionic surfactants, solvents or wetting agents. Alternatively, the propellant itself may act as a carpet cleaner.

When in use as a carpet cleaner, the product is conveniently applied to the carpet, for example by spraying from the pressurised container. After a suitable period of time, i.e. after the foaming has subsided, for example after between 10 sees and 30 mins, preferably 5 to 20 mins, the product remaining on the carpet is removed by any convenient method, for example by a domestic or industrial vacuum cleaner, or by wiping, for example with an absorbent cloth.

Suitably, the product of the present invention is a fabric care product. By "fabric care product", we include, but are not limited to, in-wash stain removers, water softeners for washing machines, spot/stain removers, ironing aids, fabric treaters, and pre- and post-wash treatments. As such, the active agent in this embodiment of the invention will be selected from those active agents which can function as fabric care products, for example surfactants, for example anionic, cationic, amphoteric OJC zwitterionic surfactants, solvents or enzymes.

Therefore, according to a further aspect of the present invention, there is provided a method of cleaning a substrate, preferably a hydrophobic entity from a substrate, said method comprising the steps of:

a) introducing onto the substrate from a pressurised container, microbial encapsulating material and a propellant, b) leaving the said material/propellant on said substrate for a period of time, c) optionally, rubbing said material into said substrate, and d) removing said material from said substrate.

Preferably, the said pressurised container further comprises at least one active agent.

Preferably, at least some of the propellant is encapsulated within the encapsulating material. More preferably, at least 1% of the propellant is encapsulated, more preferably 10% of the propellant, even more preferably at least 20% of the propellant, yet more preferably at least 40% of the propellant, yet even more preferably at least 60% of the propellant, most preferably at least 80% of the propellant is encapsulated.

Preferably, the active agent, when present and when encapsulated, is encapsulated such that at least 1% of the active agent is encapsulated, more preferably 10% of the active agent is encapsulated, even more preferably at least 20% of the active agent, yet more preferably at least 40% of the active agent, yet even more preferably at least 60% of the active agent, most preferably at least 80% of the active agent is encapsulated.

Step (b) of the above method should be performed for a time sufficient to allow said material to penetrate into the substrate and thus effect efficient, thorough, and eep' cleaning. For example, the material is suitably left on the substrate for a time between 5 sees and 24 hrs, preferably between 10 sees and 1 hr, most preferably between 15 sees and 5 mins, for example, 2 mins.

Step (d) of the above method can be performed by any convenient removal method, for example by the action of a domestic or industrial vacuum cleaner, wiping, for example wiping with an absorbent cloth, and the like.

In view of the advantages of using the product of the present invention, uses whereby a crackling, vigorous and long-lasting foam is an advantage are preferred. Moreover, in view of the difference in action of the product on hydrophilic and hydrophobic substrates, uses whereby distinguishing between hydrophobic and hydrophilic areas of a substrate are also preferred. A further advantage of products of the present invention is that the microbial encapsulating material, particularly where such material is a yeast, will, once emptied of propellant and active, retain an affinity for hydrophobic moieties. Thus, as noted hereinbefore, when the product is applied to a hydrophobic substrate, the foam will be more vigorous and long-lasting and the emptied microbial encapsulating material will take up the hydrophobic moieties on the substrate. In this way, it is possible to have the product produce a vigorous and long-lasting foam on the hydrophobic, as opposed to hydrophilic, areas of the substrate, and take up the hydrophobic moieties into the now-emptied microbial encapsulating material. In effect, the product will, by its different foaming action, identify the hydrophobic region, produce a long-lasting but vigorous foam in this region, and finally, take up at least some of the hydrophobic moieties into the empty microbial encapsulating material. If the hydrophobic moiety represents an oily stain on a substrate, the advantages of a product of the present invention as a cleaning agent are clear, the removal of oily stains being a particular problem in the art.

Thus, the product will enable the consumer to identify/detect hydrophobic stains. This is particularly important as hydrophobic stains are not always visible to the consumer but quite often contribute to malodour and to bacterial growth. Thus, the product assists the consumer in focusing cleaning effort in the very areas that such effort is particularly required in order to produce the best results as far as combating malodour, bacterial growth, and the like, is concerned. A yet further advantage of encapsulating the propellant and active agent (when present) in the microbial encapsulating material is that said encapsulating material will help to protect said propellants and active ingredients from extremes of temperature (both high and low) , UV light, pressure (both high and low) , and degradation in the air. It will be appreciated that protection from both temperature extremes and pressure is a distinct advantage in pressurised container environments. Moreover, when the product is to be used in cleaning applications, the pH of the container environment is likely to be high. i.e. above pH 7, for instance in the range pH 7.5 to 13, preferably in the range pH 7.5 to 11, although it is also possible for the pH of the container environment to be low, for example, in the pH range 2-7.5, for example pH3, although in certain cases the pH could be as low as 0.5, especially wherein the container comprises a corrosion-inhibitor, or wherein the container itself is made of plastic or is protected by a lacquer coating. In such cases, the microbial encapsulating material will assist in protecting the propellants and active ingredients from any damaging effects of this high or low pH environment, or equally, the propellant and/or its solvent (when present) protects the active ingredients from such effects.

A yet still further advantage of the present invention is the fact that the release of the propellant and active ingredient (when present) is some-what slower than is the case when no encapsulating material is present, i.e. when the pressurised container simply contains propellant (s) and active (s) . The increase in time between application from the pressurised container and the propellant and active agent (when present) being in direct contact with the substrate ensures that the propellant and active agent have had more chance to penetrate deeper into the substrate. It can be envisaged that such will be particularly advantageous when cleaning a surface such as a fabric, or a carpet, whereby the product of the invention will ensure that the propellant and active agent

(when present) penetrate deeper into the substrate, together with the microbial encapsulating material, thus effecting a deeper, improved clean of the substrate.

An even yet still further advantage of the present invention is that the foam that results from using the product of the present invention is not off-white. When used in cleaning operations, there is a tendency for the user to be discouraged from using products which are off- white, or which tend to leave an off-white residue in use, and therefore use of the products of the invention will promote user compliance.

Moreover, the active agent can be colourless when encapsulated, but become coloured when released, thus clearly enabling the consumer to see the areas where the encapsulated material/propellant/active agent mix is present. The change of colour can take place by any suitable chemical reaction, for example, by oxidation and the like.

In view of the fact that the material which promotes release of the propellant (and active agent when present) from the microbial encapsulating material can be a mucous membrane, pressurised container products of the present invention are useful in a wide variety of fields where the slow and area-specific release of propellant (and active agent when present) is advantageous. For example, and by no means limiting, the product could be used in cosmetics (hair mousses, shampoos, hair sprays, shaving foams, deodorants, coolants, breath fresheners, and the like) , food applications (creams /foams, cheese, novelty sweets, and the like) , veterinary/healthcare applications

(flea/tic sprays, oil identification and removal from contaminated wildlife, anaesthetic sprays, antihistamines, asthma inhalers, topical and oral painkillers, footsprays, smoking cessation products, and the like) , and in the engineering field (expanding foams, fillers, glues, water repellents, degreasers, anti-static products, and the like) .

Suitably, water is used to form the aqueous solution in the container of the invention is purified water, preferably de-ionised water. Preferably, the water is present in at least 20% by weight of the water/propellant/active ingredient (agent) /microbial encapsulating material mixture in the container, more preferably at least 75% by weight, even more preferably between 75% and 95% by weight, most preferably between 80% and 90% by weight.

Suitably, the amount of microbial encapsulating material present in the water/propellant/active ingredient (agent) /microbial encapsulating material mixture in the container is from 0.1 to 40% by weight of the mixture, preferably from 0.1 to 30% by weight, more preferably from 0.2 to 4% by weight, yet more preferably from 0.5 to 3% by weight, even more preferably from 0.7 to 2% by weight, most preferably from 0.8 to 1.5% by weight, for example 1% by weight.

Suitably, the amount of propellant in the water/propellant/active ingredient (agent) /microbial encapsulating material mixture in the container is from 1 to 60% by weight of the mixture, preferably from 1 to 40% by weight, more preferably from 1 to 20% by weight, even more preferably from 3 to 15% by weight, yet more preferably from 4 to 10%, and most preferably from 5 to 8% by weight, for example about 6.9 wt%.

When the propellant comprises a mixture of more than one aliphatic hydrocarbons and/or fluorinated hydrocarbons, the relative proportions can be adjusted to give optimum performance, whilst remaining within the ranges of propellant wt% given above. For instance, in the preferred case of the propellant comprising a mixture of n-butane and i-pentane, the respective amounts in the overall mixture are suitably in the range of n-butane : i- pentane of 5:1 to 1:5, preferably 4:1 to 1:4, most preferably 3:1 to 1:3, for example 5:1.9.

Suitably, the amount of active agent in the water/propellant/active ingredient (agent) /microbial encapsulating material mixture in the container is from 0.01 to 15% by weight, preferably from 0.01 to 10% by weight, more preferably from 0.05 to 8% by weight, even more preferably 0.1 to 6% by weight. Amounts of active agent less than 0.01 wt% will tend not to be sufficiently effective for the intended purpose; however, where the amount of active agent exceeds 15% by weight, the agent may become difficult to disperse. Preferably, the product of the invention may further comprise at least one surfactant. Such surfactants can be either cationic, anionic, zwitterionic, amphoteric or non- ionic surfactants, or any mixture of the different types. Preferred are anionic surfactants, or mixtures of anionic/non-ionic surfactants and cationic/non-ionic surfactants. Suitably, the surfactants should be present in the range 0.1 to 20% by weight, preferably in the range 0.5 to 10% by weight, based on the total weight of the surfactant/water/propellant/active ingredient

(agent) /microbial encapsulating material mixture.

Nevertheless, the microbial encapsulating material may itself stabilise foam and in such cases, no separate surfactant is required.

Although water is a preferred vehicle for the compositions found within and forming part of the pressurised container products of the present invention, other suitable vehicles can be employed from the following: alkylene glycols, polyalkylene glycols, vegetable oils and mixtures thereof, hydrocarbons and mixtures thereof, silicone oils. As examples, the following are particularly preferred: propylene glycol, dipropylene glycol, polypropylene glycol 2000, 4000, polyethylene glycol 200-600, glycerol, 2- methyl-2, 4-pentanediol, 1,3-butylene glycol, 1,2,6- hexanetriol, 2-ethyl-l, 3-hexanediol, and the like and vegetable oils such as safflower, castor, sesame, olive, soybean, cottonseed, peanut oil, and the like, and branched and linear hydrocarbons containing between 8 and 20 carbon atoms inclusive, and low molecular weight linear and cyclic silicone oils. Especially preferred are polyethylene glycol 200 and safflower oil.

Where the vehicle is other than water, all reference to water and aqueous solution, and the like, found elsewhere in this specification are to be interpreted accordingly as referring to the vehicle and solution in the vehicle, and the like.

The pressurised containers of the present invention are formed by introducing therein the microbially encapsulated propellants and active agent (s) (where present) as described hereinbefore.

Thus, according to a yet further aspect of the present invention, there is provided a process for the preparation of a pressurised container, wherein said container comprises therein a microbial encapsulating material, and a propellant, said process comprising the steps of:

a) encapsulating at least a proportion of said propellant in said microbial encapsulating material, and b) introducing said encapsulating material, and propellant into said pressurised container.

Suitably, steps a) and b) of the process can be performed in any order .

Preferably, at least 1% of the propellant should be encapsulated, more preferably 10% of the propellant, even more preferably at least 20% of the propellant, yet more preferably at least 40% of the propellant, yet even more preferably at least 60% of the propellant, most preferably at least 80% of the propellant is encapsulated.

The second and third aspects of the present invention may incorporate any one or more of the preferred features or embodiments of the first aspect of the invention except of course where such features or embodiments are mutually exclusive or incompatible.

It will be appreciated that the present invention offers many benefits to the consumer/user. In particular, the products enable active agents/propellants to be encapsulated in stable, secure environments and released at a rate to suit the particular application. Moreover, the product is able to differentiate between hydrophilic and hydrophobic substrates and assist in the removal of hydrophobic moieties from surfaces. In addition, the encapsulation of the active agent/propellant increases the time that elapses whilst the active agent is being introduced to the substrate. Finally, the product of the invention produces foams with advantageous characteristics to the user of the product.

In order that the invention be better understood, embodiments of it will now be described further by way of the following illustrative and non-limiting examples. These examples are to be viewed as being illustrative of specific materials falling within the broader disclosure presented above and are not to be viewed as limiting the broader disclosure.

Example 1

Preparation of Pressurised Container Samples (Samples A-K)

In the Examples, the yeast particles were on average 10 microns in size and were supplied by Micap pic (Newton-le- Willows, UK) and sourced from Aventine Renewable Energy Inc (Pekin, Illinois, USA) . Isopentane (2-methylbutane) and pentane was supplied by Fisher. Butane was supplied by Calor. Samples were made as per the details in Table 1 below.

Table 1 All samples were introduced into 400ml pressurised containers. As noted in Table 1, all samples contained 5 wt% butane.

Cooking spray oil (Fry Light sunflower spray from St Giles Foods Limited) was applied as a fine mist using an artists' spray pack to one half of carpet substrate and one half of a mirror substrate. The area to which the oil was applied is hereinafter known as the treated area. Samples B, D, F, H, I, and K were pressurised container products of the present invention.

Samples A, C, E, G, and J were comparative examples. Sample A did not foam on either half of either substrate. Sample B foamed slightly on the untreated area of the carpet substrate. This foam disappeared quickly. Sample C did not foam on either half of either substrate. Sample D foamed slightly on the untreated area of the carpet substrate. This foam disappeared quickly.

Sample E did not foam on either half of either substrate. Sample F foamed slightly on the untreated area of the carpet substrate. This foam disappeared quickly. Sample G foamed quite vigorously on both sides of the carpet substrate. Initially. The foam on the treated side of the carpet substrate was more broken than the foam on the untreated side. However, 1 minute after application, the foam was much more sustained on the treated carpet substrate compared to the untreated carpet substrate. Sample H only foamed on the treated and not the untreated half of the carpet substrate. This initial foam on the treated half of the carpet substrate was sustained after 1 minute. The same effect was seen on the mirror substrate. Sample I mainly foamed on the treated and not the untreated half of the carpet substrate. This initial foam on the treated half of the carpet substrate was sustained after 1 minute. On the mirror substrate, the initial foam on the treated half was sustained for 30 sees. Sample J initially foamed on both sides of the carpet substrate. This foam was sustained after 1 minute on the treated half only. On the mirror substrate, foam was initially present and sustained on both halves. Sample K initially foamed only on the treated half of the carpet substrate. This foam was sustained for over 1 minute. On the mirror substrate, more foam initially formed on the treated half, and after 30 sees, only the treated half had any foam. The above observations can be assessed as follows.

Sample A showed neither an initial nor a prolonged foam on either the treated or untreated areas of the carpet or the mirror. Sample B differs from Sample A in that a slight initial foam appeared on the untreated area of the carpet. This highlights the fact that the presence of the yeast is delaying the release of the butane. However, in this case, a hydrophilic environment, where the butane is released more slowly, is required to show any foam at all. The release of the butane from the yeast is still sufficiently quick that on the hydrophobic substrate, the butane is released too quickly for a visible foam to form. Moreover, even in the hydrophilic environment, where an initial foam forms, the release of butane is sufficiently quick for the foam to quickly disappear.

Similar effects are seen for the pairs: Samples C/D and Samples E/F. In each case the nature of the propellant was different: butane only (Samples A and B) , butane and pentane (Samples C and D) , butane and isopentane (Samples E and F) .

Sample G differs from Sample A as it contained 95% of a standard bathroom cleaning formulation rather than 95% de- ionised water. The standard bathroom cleaning formulation used was a water/surfactant mix with the following composition: De-ionised water 3450.20 Dissolvene EDG 520.00 Alfonic 3.60 Sodium hydroxide (50%) 8.52 Categene 818 9.20 Sodium molybdate 4.00 Ammonium hydroxide (30%) 1.68 SRG 1049 Citrus 2.80

The values given above are weights (in g) per 4 litres of formulation mix. Alfonic and Categene 818 are the surfactants in the formulation mix. The mix was formed by adding the ingredients in the order shown above, with constant mechanical stirring. A minute or two was left between adding each ingredient to ensure homogeneity.

Sample G produced a vigorous foam on the carpet substrate. Initially the foam was more broken on the hydrophobic area. Compared with Sample A, the benefits of the substitution of the standard bathroom cleaning formulation for water are clearly demonstrated. There was no discernible difference between the hydrophobic and hydrophilic areas of the mirror substrate, either initially or after 1 minute. In conclusion, Sample G gave very little discrimination initially between hydrophilic/hydrophobic areas on the carpet substrate, but did discriminate the hydrophobic area after 1 minute. However, Sample G was unable to discriminate between hydrophobic/hydrophilic areas on the mirror substrate at any time. Sample H, on the other hand, additionally contained 1% yeast (in place of a similar amount of bathroom cleaning formulation mix) . This lead to a clear discrimination of the hydrophobic area as opposed to the hydrophilic area, both initially and over a sustained period of 1 minute or so, on both carpet and mirror substrates. In this case, release of the butane from the yeast is slower than in Sample B and hence the quickening effect of the hydrophobic surface is enough to produce the foam. On the hydrophilic area, release is just too slow to form a foam at all.

Sample I is similar to Sample H but contains 94% of de- ionised water/surfactants (composed of 93.68% de-ionised water and 0.32% surfactants), instead of 94% bathroom cleaning formulation mix. Sample I shows similar benefits to Sample H, although there is no initial discrimination on the mirror substrate and the discrimination after time is not as noticeable.

Sample J is similar to Sample G apart from the nature of the propellant. As with Sample G, Sample J showed a sustained foam on the hydrophobic area of the carpet substrate. Furthermore, as with Sample G, Sample J showed no discernible difference between the hydrophobic and hydrophilic areas of the mirror substrate, either initially or after 1 minute.

Sample K additionally contained 1% yeast compared with Sample J (in place of a similar amount of the standard bathroom cleaning formulation mix) . Sample K produced optimum results similar to the results exhibited by Sample H, a clear discrimination of the hydrophobic area as opposed to the hydrophilic area, both initially and over a sustained period of 1 minute or so, on both carpet and mirror substrates. Once again, similar to Sample K, the release of butane/isopentane from the yeast is slower than in the equivalent water-based sample, Sample F, and hence the quickening effect of the hydrophobic surface is enough to produce the foam. On the hydrophilic area, release is just too slow to form a foam at all.

Example 2

Preparation of a Household Cleanser

A household cleanser composition of the following formulation was prepared: nonoxynol 9 (15 wt%) , lauramide DEA (2 wt%) , polyethyleneglycol 200 (43 wt%), and yeast (40 wt%) .

The household cleanser composition as noted above was then pressurised in a container with isobutane (70 wt% cleanser to 30 wt% isobutane propellant) to produce a product which exhibited a long-lasting, crackling foam effect upon discharge. The product had the following overall composition: nonoxynol 9 (10.5 wt%), lauramide DEA (1.4 wt%), polyethylene glycol 200 (30.1 wt%), yeast (28.0 wt%) , and isobutane (30 wt%) .

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A product comprising a pressurised container, wherein said container comprises therein a microbial encapsulating material, and a propellant.

2. A product as claimed in claim 1 wherein said container further comprises at least one active agent.

3. A product as claimed in either one of claims 1 and 2 wherein said microbial encapsulating material is yeast .

4. A product as claimed in any one of the preceding claims wherein said propellant comprises one or more aliphatic hydrocarbons, one or more fluorinated hydrocarbons, or mixtures thereof.

5. A product as claimed in any one of the preceding claims wherein said propellant is encapsulated within the encapsulating material such that at least 1% of the total amount of propellant in the product is encapsulated.

6. A product as claimed in claim 5 wherein said encapsulation is such that at least 20% of the total amount of propellant in the product is encapsulated.

7. A product as claimed in claim 5 wherein said encapsulation is such that at least 60% of the total amount of propellant in the product is encapsulated.

8. A product as claimed in any one of the preceding claims wherein said product functions as a cleaning product .

9. A product as claimed in any one of claims 2 to 8 wherein said active agent is encapsulated within the encapsulating material such that at least 1% of the total amount of active agent in the product is encapsulated.

10. A product as claimed in claim 9 wherein said encapsulation is such that at least 20% of the total amount of active agent in the product is encapsulated.

11. A product as claimed in claim 9 wherein said encapsulation is such that at least 60% of the total amount of active agent in the product is encapsulated.

12. A method of cleaning a substrate, said method comprising the steps of:

a) introducing onto the substrate from a pressurised container, a microbial encapsulating material and a propellant, as defined in any of the preceding claims, b) leaving the said material/propellant on said substrate for a period of time, c) optionally, rubbing said material into said substrate, and d) removing said material from said substrate.

13. A method as claimed in claim 12 wherein said pressurised container further comprises at least one active agent.

14. A process for the preparation of a pressurised container, wherein said container comprises therein a microbial encapsulating material, and a propellant, as defined in any one of claims 1 to 11, said process comprising trie steps of:

a) encapsulating- at least a proportion of said propellant in said microbial encapsulating material, and b) introducing said encapsulating material, and propellant into said pressurised container.

15. A process as claimed in claim 14 wherein said pressurised container further comprises at least one active agent .