Patent Application
20250161178
The present disclosure relates to a depilatory composition comprising a depilatory active, an alkali metal hydroxide and an aminoalkylpropanol and having a pH at 20° C. in the range 10 to 12.5. The compositions provide effective hair removal within an acceptable contact time yet are well tolerated by the skin. A method of removing hair and a method of producing the compositions are also provided.
Compositions for removing superfluous hair from mammals are well known. Such compositions include depilatory compositions which comprise a compound that degrades the keratin within the hair thus weakening it and allowing for removal. The depilatory compositions are applied to the area containing the superfluous hair, allowed to remain thereon to degrade the hairs and then removed from the area together with the degraded hairs.
Depilatory compositions of this type typically comprise depilatory compounds which have a thiol group, such as potassium thioglycolate, and also typically contain potassium hydroxide to provide a high pH which aids hair removal efficacy. However, there is a significant disadvantage in using such compositions in that they can irritate and even damage the skin as a result of the high pH (usually above 12). The potential for skin irritation and damage increases with the length of time that the depilatory compositions are left in contact with the skin. Unfortunately, in order to obtain acceptable hair removal, it can be necessary to leave the depilatory composition in contact with the skin/hair for a longer contact time than the skin can easily tolerate without being susceptible to irritation or even damage.
There is therefore a need within the art to provide depilatory compositions which ameliorate one or more of the above disadvantages with known compositions. In particular there is a need within the art to provide depilatory compositions which provide for effective hair removal yet without unduly irritating or damaging the skin. In particular there is a need to provide such compositions which can be used for effective hair removal within an acceptable application time, such as (but not limited to) less than 10 minutes and ideally 7 minutes or less in order to reduce the likelihood of skin irritation/damage.
Furthermore, there is a need in the art to be able to produce such compositions easily and conveniently without unacceptable levels of thickening (which can lead to production and processing difficulties). There is a further need in the art to produce such compositions which are stable on storage and which show good pH stability.
It is an object of the present disclosure to provide depilatory compositions comprising a depilatory active which address one or more of the above disadvantages. In particular, it is an object of the present disclosure to provide such depilatory compositions which provide effective hair removal yet which are well tolerated by the skin. It is a further object of the present disclosure to provide such compositions which exhibit good hair removal properties with a contact time of 10 minutes or less, such as (but not limited to) 7 minutes or less. It is a further object of the present disclosure to provide such compositions which can be produced easily, and, which are stable on storage and which show good pH stability.
Surprisingly, it has been found that one or more of the aforementioned disadvantages can be addressed by the inclusion of an aminoalkylpropanol, especially aminomethylpropanol, in depilatory compositions comprising a depilatory active and by formulating such a composition to have a pH at 20° C. in the range of from 10 to 12.5.
GB1 064 388 discloses substituted thiol based depilatory actives used in an emollient base which provides a mantle to prevent skin irritation by the depilatory actives.
GB 1 329 029 discloses a self-heating depilatory composition comprising a thioglycollate. A pH of 10 to 12.5 is disclosed for the compositions.
JP 08-012531 discloses hair growing agents which may comprise potassium hydroxide and 2 amino-2-methylpropanol. No examples are given of depilatory compositions comprising 2 amino-2-methylpropanol. The compositions are also described as depilatory compositions in the document but no depilatory actives are disclosed.
According to an aspect of the present disclosure, there is provided a depilatory composition comprising: a depilatory active; an alkali metal hydroxide selected from the group consisting of sodium hydroxide and/or potassium hydroxide; and an aminoalkylpropanol, wherein at 20° C. the composition has a pH in the range of from 10 to 12.5.
In another aspect, the present disclosure provides a method of removing hair from the bodily surface of a mammal, the method comprising: (i) applying a composition according any of the embodiments described herein to the bodily surface of a mammal from where it is desired to remove hair; (ii) allowing the composition to contact the bodily surface for a period of time of from 1 to 10 minutes; and (iii) subsequently removing at least a portion of the composition from the bodily surface.
In another aspect, the present disclosure provides a method of producing a composition according any of the embodiments described herein, the method comprising: (i) providing an intermediate composition comprising the depilatory active and the alkali metal hydroxide; and (ii) adding the aminoalkylpropanol to the intermediate composition.
In another aspect, the present disclosure provides a depilatory composition comprising: a depilatory active; urea; a carbomer; and a gum.
According to a first aspect of the present disclosure, there is provided a depilatory composition comprising: a depilatory active; an alkali metal hydroxide selected from the group consisting of sodium hydroxide and/or potassium hydroxide; and an aminoalkylpropanol, wherein at 20° C. the composition has a pH in the range of from 10 to 12.5.
It has been found that compositions according to the present disclosure provide for good hair removal properties yet are well tolerated by the skin. Furthermore, the compositions provide for good hair removal within acceptable contact times with the skin/hair which further reduces the risk of skin irritation/damage. Typically, a contact time of 10 minutes or less is required for the compositions of the present disclosure to provide for effective hair removal and contact times of 7 minutes or less can be provided according to some embodiments of the present disclosure.
According to a second aspect of the present disclosure there is provided a method of removing hair from a bodily surface of a mammal, the method comprising the steps of:
The method of the second aspect of the present disclosure provides for the same advantages as the first aspect of the present disclosure with respect to the advantages regarding hair removal efficiency and skin tolerance.
According to a third aspect of the present disclosure there is provided a method of producing a composition according to the present disclosure, wherein the method comprises the step of the addition of the aminoalkylpropanol to a composition comprising a depilatory active and an alkali metal hydroxide.
It has been found that this method of the present disclosure provides a convenient way of producing the compositions of the present disclosure without undue thickening of the compositions occurring.
The compositions of the present disclosure comprise a depilatory active, an alkali metal hydroxide selected from sodium hydroxide and/or potassium hydroxide and an aminoalkylpropanol, and the compositions have a pH at 20° C. the range of from 10 to 12.5.
By the term “depilatory active” as used herein is meant a compound which acts upon the keratin in the hair to chemically degrade it by breaking down the disulphide bonds in the keratin. This chemical degradation weakens the hair and allows for the degraded, and thus weakened, hair to be removed. It does not include rosin materials or waxes or any other ingredient(s) which do/does not exert a chemical-degradation action on the hair, but which rather, provide(s) an epilatory effect by adhering to the hair.
By the term “bodily surface” as used herein is meant an external surface of a mammal including but not limited to the head, face and body. Mucosal membranes are not included within this definition of “bodily surface”.
The pH of the compositions as referred to herein is the pH of the composition at 20° C.
Unless otherwise stated all amounts are given herein as wt % based on the total weight of the composition.
The depilatory compositions of the present disclosure may be of any suitable form. Non-limiting examples of forms for the compositions include gels, mousses, foams, creams, lotions or peelable films. The form may be chosen according to the intended area of application for the compositions. Particular (but non-limiting) forms of the compositions include gels, creams, mousses, foams and peelable films. Some consumers prefer to use a composition which is not opaque. Thus, according to one non-limiting embodiment of the present disclosure the compositions are translucent or transparent. Transparent or translucent gels, mousses, foams or peelable films may be utilized in certain non-limiting embodiments of the present disclosure. Specific non-limiting examples are transparent or translucent gels.
The depilatory active present in the compositions of the present disclosure may be any compound which provides for the removal of hair by a chemical reaction, such as by degrading the keratin present in the hair. In certain particular (but non-limiting) embodiments, the depilatory active contains a thiol group and most especially that the depilatory active which contains a thiol group is selected from one or more of the group consisting of potassium thioglycolate, calcium thioglycolate, thioglycolic acid, dithioerythritol, thioglycerol, thioglycol, thioxanthine, thiosalicylic acid, N-acetyl-L-cysteine, lipoic acid, sodium dihydrolipoate 6,8-dithiooctanoate, sodium 6,8-diothiooctanoate, a hydrogen sulphide salt, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, ammonium thioglycolate, glyceryl monothioglycolate, monoethanolamine thioglycolate, monoethanolamine diammoniumdithiodiglycolate, ammonium thiolactate, monoethanolamine thiolactate, thioglycolamide, homocysteine, cysteine, glutathione, dithiothreitol, dihydrolipoic acid, 1,3-dithiopropanol, thioglycolamide, thioglycol-hydrazine, keratinase, guanidine thioglycolate, and cysteamine.
According to one embodiment of the present disclosure the depilatory active comprises at least one of potassium thioglycolate, calcium thioglycolate and thioglycolic acid, in particular at least one of potassium thioglycolate and thioglycolic acid. Typically, the compositions include a thioglycolic acid salt, such as potassium thioglycolate and/or calcium thioglycolate. Whilst the compositions are typically prepared using the thioglycolates, during storage at least some of the thioglycolate is converted to thioglycolic acid.
In certain non-limiting embodiments, the depilatory active is present in an amount of from 0.5 to 10 wt %, such as (but not limited to) 1 to 9 wt %, or 1.5 to 7 wt %, e.g. 2 to 6 wt % based on the total weight of the depilatory composition. In certain particular (but non-limiting) embodiments, the compositions of the present disclosure comprise potassium thioglycolate and/or sodium thioglycolate and/or thioglycolic acid in the aforementioned amounts (in total if more than one of these are present). In certain particular (but non-limiting) embodiments, the compositions comprise the aforementioned amounts of potassium thioglycolate and/or thioglycolic acid.
The compositions of the present disclosure further comprise an alkali metal hydroxide selected from sodium hydroxide and/or potassium hydroxide as a source of alkalinity. In certain particular (but non-limiting) embodiments, at least 50 wt % thereof is potassium hydroxide (based on the total weight of the alkali metal hydroxide in the composition).
In certain non-limiting embodiments, the alkali metal hydroxide is present in a total amount of from 0.5 to 5 wt % (by weight of the composition), such as (but not limited to) 1 to 3 wt %, or 1.5 to 2.5 wt %, e.g. 1.75 to 2.25 wt %. In particular (but non-limiting) embodiments, the compositions of the present disclosure comprise potassium hydroxide in these amounts, such as (but not limited to) 1.5 to 2.5 wt %.
The amount of the alkali metal hydroxide added will depend upon the desired pH of the depilatory composition and other formulation considerations. However, it has been found that good hair removal properties and acceptable contact times combined with the compositions being well tolerated by the skin are achieved with compositions according to the present disclosure which contain the above amounts of the alkali metal hydroxide.
The compositions of the present disclosure comprise an aminoalkylpropanol.
Without wishing to be bound by theory, the presence of the aminoalkylpropanol, is believed to allow for the depilatory compositions of the present disclosure to be formulated at a pH at 20° C. in the range of from 10-12.5, (which is lower than many depilatory compositions which act by chemically degrading the keratin in the hair) yet still provide for effective hair removal and have a contact time in use which is sufficiently short that it does not lead to unacceptable levels of skin irritation.
Any aminoalkylpropanol may be used according to the present disclosure, such as aminomethylpropanol, aminoethylpropanol or aminopropylpropanol. However, in certain non-limiting embodiments, the aminoalkylpropanol comprises aminomethylpropanol, and in certain particular (but non-limiting) embodiments is aminomethylpropanol.
In certain non-limiting embodiments, the aminoalkylpropanol is present in the compositions an amount of from 0.2 to 10 wt %, based on the total weight of the composition. In certain particular (but non-limiting) embodiments, the aminoalkylpropanol is present in an amount of from 0.5 to 5 wt %, such as (but not limited to) 0.75 to 4.5 wt %, or 1 to 4 wt %, or 1.5 to 3.5 wt %. In certain particular (but non-limiting) embodiments, the compositions of the present disclosure comprise the aforementioned amounts of aminomethylpropanol.
According to one non-limiting embodiment of the present disclosure the weight ratio of the aminoalkylpropanol to alkali metal hydroxide is in the range 3:1 to 1:1, such as (but not limited to) 2:1 to 1:1, or 1.5:1 to 1:1. In certain particular (but non-limiting) embodiments, in the compositions there is weight ratio of the aminomethylpropanol to potassium hydroxide of from 3:1 to 1:1, such as (but not limited to) 2:1 to 1:1, or 1.5:1 to 1:1.
In certain particular (but non-limiting) embodiments, the compositions of the present disclosure comprise potassium thioglycolate and/or thioglycolic acid, potassium hydroxide and aminomethylpropanol. In certain particular (but non-limiting) embodiments, the composition comprises from 2 to 6 wt % potassium thioglycolate and/or thioglycolic acid, from 0.5 to 5 wt % potassium hydroxide and from 0.75 to 4.5 wt % aminomethylpropanol.
It has been found that the inclusion of the aminoalkylpropanol, especially the aminomethylpropanol, in the claimed depilatory compositions provides for a high degree of depilation but at a lower pH than is usual for conventional depilatory compositions. Typically, depilatory compositions have a pH of about 12.5 at 20° C. One advantage of formulating products at lower pHs is that they are typically better tolerated by the skin.
pH
The compositions of the present disclosure have a pH in the range of from 10 to 12.5. In certain particular (but non-limiting) embodiments, the compositions have a pH in the range of from 10.2 to 12, such as (but not limited to) from 10.3 to 11.8, or 10.4 to 11.6, e.g. 10.5 to 11.5 and particularly (but not by way of limitation) 10.6 to 11.3, including all ranges in between these ranges. It has been found that the compositions of the present disclosure can be formulated to pHs below 11, yet, still provide effective hair removal from an acceptable contact time. A pH range of 10.7 to 11.1 has been found to be utilized in certain non-limiting embodiments of the present disclosure. Therefore, in a particular (but non-limiting) embodiment, the compositions of the present disclosure have a pH of 11 or below.
In particular (but not by way of limitation), a pH in the range of from 10.4 to 11.6 and a contact time of from 2 to 7 minutes may be utilized according to the present disclosure, such as (but not limited to) a pH in the range of from 10.5 to 11.5 and a contact time of 2 to 7 minutes, or a pH in the range of from 10.6 to 11.3 and a contact time of from 2 to 7 minutes. The pHs herein are those at 20° C.
The compositions of the present disclosure may contain additional optional ingredients. Such optional ingredients may vary according to the physical format of the compositions and other formulation considerations.
The compositions may comprise components which accelerate the keratin degradation reaction in the hair such as urea, thiourea, dithioerythritol, dimethyl isosorbide (DMI), ethoxydiglycol (Transcutol®) or methyl propyl diol (MT diol). The compositions desirably comprise from 1 to 15 wt % of the accelerator based on the total weight of the composition, such as (but not limited to) from 2 to 13 wt %, or 4 to 12 wt %, or from 5 to 10 wt %. In certain particular (but non-limiting) embodiments, the compositions of the present disclosure comprise urea as an accelerator, particularly in an amount of from 2, 3 or 5 wt % to 10 wt %, especially 6 to 9 wt %, such as up to 7 wt % or 8 wt %. It has been found that for a given composition the hair removal efficacy increases with an increasing concentration of accelerator, especially urea. However, the inclusion of urea in a composition can be associated with odours which consumers may find undesirable. Thus, there is a need to produce compositions which are effective for hair removal but which do not exhibit an unacceptable level of malodour. Furthermore, the use of high concentrations of accelerators, such as urea, can cause the pH of the compositions to become unstable with time and to drift upwards to produce a more alkaline composition. This is undesirable as the more alkaline a composition is, the less it is well-tolerated by the skin. The above amounts have been found to provide a balance of efficacy and malodour control.
Certain particular (but non-limiting) embodiments of the compositions of the present disclosure comprise a gelling agent which can help to produce the desired rheological properties for the depilatory compositions of the present disclosure. The inclusion of a gelling agent has also been found to aid the hair removal efficacy of the compositions and therefore gelling agents are utilized in certain non-limiting embodiments as optional ingredients according to the present disclosure. Suitable gelling agents include acrylate-based polymers, such as a carbomers. Other suitable gelling agents are alkyl vinyl ether/maleic anhydride copolymers such as methyl vinyl ether/maleic anhydride (PVM/MA) copolymer crosslinked with decadiene.
The inclusion of acrylate-based polymers, and particularly (but not by way of limitation) carbomers, may be utilized according to the present disclosure, especially in combination with urea, and in certain particular (but non-limiting) embodiments also with a gum such as xanthan gum.
The compositions of the present disclosure may therefore also contain an acrylate-based polymer, such as (but not limited to) a carbomer. Suitable carbomers include the carbomers available under the tradename Carbopol®, available ex Lubrizol. Typically, if present, the carbomer is included in the composition in an amount of 0.25 to 5 wt %, such as (but not limited to) 0.5 to 5 wt %, or 0.75 to 4 wt %, or 1 to 3 wt %.
When a carbomer is present in the compositions of the present disclosure, according to one aspect of the present disclosure it has further been found to be advantageous if urea and/or a gum, especially Xanthan gum, is also present in the composition, particularly if the composition is a gel. The particular (but non-limiting) amounts of the carbomer, urea, and gum are as given hereinabove. The combination of the carbomer and the urea has been found to lead to enhanced hair removal results in the compositions of the present disclosure and the effect has been found to be further enhanced by the inclusion of a gum, especially xanthan gum. Also, it has been found that these combinations allow lower levels of the depilatory active and/or of the aminoalkylpropanol to be used, whilst maintaining efficacy of hair removal obtained from the use of the compositions. A particular (but non-limiting) option according to the present disclosure is the combination of a carbomer used in with urea and xanthan gum, with the amounts being as given herein. It has been found that the use of carbomers, compared to other gelling agents, provide depilatory compositions which show good efficacy but which can be formulated with lower amounts of accelerators, such as urea.
It has also been found that, surprisingly, the combination of certain accelerators, gelling agents, and gums can provide good hair removal results in depilatory compositions comprising a depilatory active even in the absence of an aminoalkylpropanol. It has been found that the combination of urea, a carbomer, especially a carbopol and a gum, especially xanthan gum as disclosed hereinabove provides this benefit.
In certain particular (but non-limiting) embodiments, the urea is included in the compositions in an amount of from 2, 3 or 5 wt % to 10 wt %, especially 6 to 9 wt %, such as up to 7 wt % or 8 wt %. The carbomer is typically included in the depilatory composition in an amount of 0.25 to 5 wt %, such as (but not limited to) 0.5 to 5 wt %, or 0.75 to 4 wt %, or 1 to 3 wt %. The gums, especially xanthan gum, are present in an amount of from 0.05 to 5 wt %, such as (but not limited to) 0.1 to 3 wt %, or 0.1 to 0.5 wt %, or 0.2 to 0.4% wt based on the total weight of the composition.
It has been found that when the compositions of the present disclosure comprise carbopol (which has a pH of around 3 prior to neutralisation in-situ in the compositions), typically higher levels of an alkali, such as potassium hydroxide, are required to increase the pH of the compositions to a pH 10 to 12.5 and especially to above 10.5 compared to compositions which contain other gelling agents. It is acknowledged that the more alkali is present in the composition the greater is the potential for skin irritancy. However, it has been found that the amount of alkali to be added to the formulation, when AMP is used, can be kept relatively low. This allows the pH of the composition to be in the claimed range yet still provides a depilatory composition which is efficacious for hair removal. A depilatory composition with a pH of below 12 will be less irritating to skin than a composition with a pH of above 12; many commercial depilatory compositions have a pH of above 12, such as about 12.5. Also, it has been found that for compositions comprising AMP the amount of KOH added to the compositions can be kept relatively low, in particular for compositions having a pH up to about 11.5 whilst still providing effective depilatory effects.
As an alternative to the gelling agent, the compositions of the present disclosure may contain viscosity increasing agent, especially a silica-based one, such as clay-based synthetic silicas. Suitable examples of silica-based viscosity increasing agents include Magnesium Aluminum Silicate, Magnesium Silicate, Magnesium Trisilicate, Lithium Magnesium Silicate, Lithium Magnesium Sodium Silicate and also clays such as montmorillonite, attapulgite, bentonite and hectorite. These materials are typically used in the compositions of the present disclosure in an amount of from 0.1 wt % to 5 wt %, especially 0.5 wt % to 3 wt %, such as 0.75 wt % to 2 wt %. It has been found that a when a silica-based viscosity increasing agent is used, it is beneficial to also include an anionic acrylic polymer emulsion copolymer, such as one of the Aculyn polymers available from Dow Chemical in the compositions as this combination has been found to give good hair removal results. In certain particular (but non-limiting) embodiments, amounts of the anionic acrylic polymer emulsion copolymer are in the range 0.005 wt % to 1 wt %, such as 0.01 to 0.5 wt %, e.g. 0.02 wt % to 0.2 wt %.
It has also been found that good depilatory effects can be obtained by the inclusion of an alkyl vinyl ether/maleic anhydride copolymers, such as, methyl vinyl ether/maleic anhydride (PVM/MA) copolymer crosslinked with decadiene as a gelling agent. However typically it will be necessary to formulate such a composition with a higher concentration of an accelerator, such as urea, than would be necessary for a composition comprising a carbopol. The alkyl vinyl ether/maleic anhydride copolymers are typically present in an amount of 0.5 wt % to 5 wt %, such as (but not limited to) 1 wt % to 3 wt %, or 1.5 wt % to 2.5 wt %. These amounts of the alkyl vinyl ether/maleic anhydride copolymers are typically used with at least 5 wt % of accelerator, such as (but not limited to) 5 wt % to 9 wt %, or 7 wt % to 8.5 wt %. In certain particular (but non-limiting) embodiments, urea is the desired accelerator used with these copolymers.
According to one embodiment of the present disclosure, the compositions of the present disclosure may comprise a non-ionic surfactant, especially an alkyl polyglucoside surfactant, as these have been found to further improve the properties of the composition; it is believed that these ingredients aid the penetration of the depilatory actives into the hair. Particular (but non-limiting) embodiments utilize C6 to C14 alkyl polyglucosides, and in particular, C8 to C12 alkyl polyglucosides, and C10 alkyl polyglucoside (also known as cocoglucoside). Such ingredients are present in certain non-limiting embodiments in an amount of from 0.1 to 5 wt % based on the total weight of the composition, such as (but not limited to) 0.15 to 2.5 wt %, or 0.2 to 1.5 wt %, e.g. 0.2 to 1 wt %. In certain particular (but non-limiting) embodiments, the compositions comprise cocoglucoside in the aforementioned amounts. However non-ionic surfactants are not necessarily required in all types of compositions according to the present disclosure.
In another embodiment of the present disclosure the compositions may comprise a film former, such as a methacrylate-based copolymer, to improve water resistancy of compositions. One such suitable methacrylate-based copolymer is dimethylacrylamide/acrylic acid polystyrene ethyl methacrylate copolymer which is available commercially under the tradename Invisaskin™ RB ex Grant Industries. If present, the methacrylate-based copolymer may be included in certain particular (but non-limiting) embodiments in an amount of from 0.001 to 0.5 wt %, such as 0.01 to 0.2 wt %, e.g. 0.02 to 0.1 wt %. Film former ingredients will not necessarily be included in all types of compositions according to the present disclosure. Typically, they will be included in compositions which dry to a film upon use.
Thus, according to certain embodiments of the present disclosure, the compositions comprise an alkyl polyglucoside surfactant and a methacrylate-based copolymer. A particular (but non-limiting) combination for use in the compositions of the present disclosure is cocoglucoside and dimethylacrylamide/acrylic acid polystyrene ethyl methacrylate copolymer, especially in the amounts as stated above. According to one non-limiting aspect of the present disclosure, the compositions of the present disclosure comprise potassium thioglycolate and/or thioglycolic acid, potassium hydroxide, aminomethylpropanol, an alkyl polyglucoside and/or a methacrylate-based copolymer.
According to one aspect of the present disclosure, depilatory compositions comprising the following are provided:
According to a particular (but non-limiting) aspect of the present disclosure, depilatory compositions comprising the following are provided:
According to a particular (but non-limiting) aspect of the present disclosure, depilatory compositions comprising the following are provided:
According to another particular (but non-limiting) aspect of the present disclosure, depilatory compositions comprising the following are provided:
In a particular (but non-limiting) embodiment, the depilatory compositions comprise:
The depilatory composition of the present disclosure may comprise water depending upon the physical form of the composition. However, gels, mousses foams, creams and lotions will typically comprise higher amounts of water than will a peelable film composition. Thus, the compositions of the present disclosure may be aqueous based. In certain non-limiting embodiments of gel, mousse, foam, cream and lotion compositions, the amount of water present in the compositions is at least 40 wt %, such as (but not limited to) at least 50 wt %, or at least 60 wt % or 65 wt % based on the total weight of the composition. Gel compositions comprising the aforementioned amounts of water have been found to be particularly effective according to the present disclosure. Peelable gel compositions typically comprise 40 to 75 wt % water, such as (but not limited to) 45 to 70 wt %, or 50 to 60 wt % water.
The depilatory compositions may further include a humectant. Suitable humectants include polyols, such as glycerine, propylene glycol and butylene glycol. In a particular (but non-limiting) embodiment, the humectant is glycerine. The humectant may be present in an amount of from 0.05 to 10 wt %, such as (but not limited to) 0.25 to 5 wt %, or 0.5 to 3 wt %.
The compositions of the present disclosure may also comprise a chelating agent. Any suitable chelating agent may be used and a particular (but non-limiting) chelating agent is sodium gluconate. Conventional amounts may be used for example 0.01 wt % to 2 wt %.
The compositions may contain fragrances and/or colouring agents in conventional amounts.
Depending upon the physical form of the composition, the composition may also contain one or more thickening agents such as one or more gums. Any suitable thickening gum may be used, such as (but not limited to) xanthan gum, particularly when used in combination with a carbomer gelling agent and urea as an accelerant. Typically, when included, the gums are present in an amount of from 0.05 to 5 wt %, such as (but not limited to) 0.1 to 3 wt %, or 0.1 to 0.5 wt %, or 0.2 to 0.4% wt based on the total weight of the composition. Such thickeners are typically used in gel compositions of the present disclosure.
If desired the depilatory compositions may further include an emollient such as an oil or a wax, especially in a cream or lotion composition. A particular (but non-limiting) oil emollient is mineral oil. A particular (but non-limiting) wax emollient is ceteareth-20. The compositions may include a mixture of an oil and a wax as a combined emollient. The oil emollient and/or the wax emollient may be included in conventional amounts.
Other components which may be incorporated into the depilatory compositions include a buffer such as sodium silicate or magnesium silicate. The depilatory composition may further comprise other salts selected from di- and tri-valent salts, such as magnesium chloride, calcium chloride ammonium chloride, magnesium sulphate, calcium sulphate, aluminium sulphate, magnesium carbonate, calcium sulphate, calcium carbonate. A particular (but non-limiting) salt is magnesium chloride. In an alternative embodiment the composition can comprise a salt extract, such as dead-sea salts. Such salts may be included in conventional amounts.
The present disclosure also provides a method of removing hair from a bodily surface of a mammal, such as the head, body or face, by;
The compositions of the present disclosure may be applied and removed by any suitable method according to the type of composition. Such methods are well known in the art. For example, a gel, cream or lotion may be applied to the area to be treated either by hand or with the aid of a device (such as a spatula, roll-on, tube applicator or similar device). Mousse or foam compositions may be applied directly from a dispensing device such as an aerosol can or pump dispenser. Typically, peelable films are applied as a gel or liquid composition and dry to form a film which is then peeled off at the end of the desired contact time.
After the required contact time between the unwanted hairs and the depilatory composition of the present disclosure has elapsed and the unwanted hairs have been degraded, the depilatory composition and the degraded hairs may be removed by any suitable means, for example, in the same way as in which the composition was applied. Typically, a spatula or similar device especially one with a substantially straight edge, or a flexible object such as a foam/tissue/cloth/wipe type object may be used to remove the depilatory composition and the degraded hairs. This is achieved simply by moving the spatula etc. or flexible object around the area to which the depilatory composition has been applied in order to ‘scoop’ up the same. In this way the depilatory composition is lifted from the area to which it has been applied and can be removed. Any residual composition may be removed by, for example, rinsing with water. Alternatively, the composition may be rinsed away with water.
The depilatory compositions of the present disclosure are typically allowed to contact the bodily surface, e.g. skin or hair, for at least 2 minutes, such as (but not limited to) at least 3 minutes or 4 minutes. However, in order to reduce any potential skin irritation from the use of the compositions of the present disclosure it is desired (but not by way of limitation) that the contact time is 9 minutes or less, such as (but not limited to) 8 minutes or less, or 7 minutes or less. Particular (but non-limiting) contact times for the compositions of the present disclosure and the hair to be removed are in the range of from 2 to 8 minutes, such as (but not limited to) 3 to 7 minutes, or 4 to 7 minutes (including ranges there-between). It has been found that the compositions of the present disclosure provide effective hair removal yet are well tolerated by the skin, when these contact times are used.
Also provided according to the present disclosure is a method of producing a composition according to the present disclosure which comprises the step of the addition of the aminoalkylpropanol to a composition comprising a depilatory active and an alkali metal hydroxide. It has been found that for some types of compositions according the present disclosure, such as gels, the addition of the aminoalkylpropanol, can thicken the composition too much and make subsequent production and processing difficult. It has been found that by adding the aminoalkylpropanol in this manner this tendency to thicken the compositions can be minimised and thus production and subsequent processing is made easier.
One particular (but non-limiting) method for producing gel compositions according to the present disclosure is:
Ideally depilatory compositions will remove as high a percentage as possible of unwanted hair in a single treatment. As the application method can vary slightly with the user (both in terms of hair type treated, application method, contact time, and personal levels of expectation, etc.), it is generally considered that hair removal results above about 50% would be considered as acceptable by the user. Results higher than this may be desired such as (but not limited to) at least 70%, or at least 80%, and particularly (but not by way of limitation) above 90%.
The use of the gelling agents, urea and gums, especially carbomers (most especially carbopols), urea and xanthan gum in depilatory compositions comprising a depilatory active has been found to be especially effective in compositions comprising an aminoalkylpropanol, such as aminomethylpropanol. However, it has also been found that this combination can provide good hair removal efficacy in other types of compositions too.
The depilatory active can be any of the types described above, especially the compositions comprising a thiol group. The depilatory compositions may further comprise an alkali metal hydroxide selected from sodium hydroxide and/or potassium hydroxide.
For the avoidance of doubt, it is to be understood that the types and amounts of the depilatory active, urea, carbomer (especially carbopol), the gums (especially xanthan gum) and the alkali metal hydroxide as disclosed herein for the other aspects of the present disclosure apply equally here, mutatis mutandis. It is also to be understood that the depilatory compositions of this aspect of the present disclosure may be of any of the physical forms disclosed herein and that any of the optional ingredients disclosed herein may be included in the depilatory compositions of this aspect.
Thus, there is also according to a further embodiment of the present disclosure depilatory compositions comprising a depilatory active (as described above and especially containing a thiol group), urea, a carbomer (especially a carbopol) and a gum, especially xanthan gum. These compositions have been found to exhibit good hair removal results. These compositions do not necessarily need to comprise an aminoalkylpropanol, such as aminomethylpropanol, and in some embodiments of the present disclosure aminoalkylpropanols are not included in the formulations. Thus, according to one aspect of the present disclosure, depilatory compositions are provided which comprise a depilatory active, urea, a carbomer, especially a carbopol and a gum, especially xanthan gum, but which do not comprise an aminoalkylpropanol, such as aminomethylpropanol.
Therefore, according to a further aspect of the present disclosure, there is also provided the use of a combination of urea, carbomer, especially a carbopol, and a gum, especially xanthan gum, to provide for efficacious hair removal in depilatory compositions comprising a depilatory active. Also provided is the use of a combination of urea, carbomer, especially a carbopol, and a gum, especially xanthan gum, to prepare a depilatory composition comprising a depilatory active.
The compositions of the present disclosure which are formulated with the combination of urea, carbomer and a gum but without the inclusion of the aminoalkylpropanol, also provide a high degree of depilation but typically at a higher pH than if the aminoalkylpropanol, had been included. This may be desirable for some depilatory compositions and also provides for different types of effective compositions to be provided.
The present disclosure will now be described in more detail with reference to the following non-limiting examples. Further examples within the scope of the present disclosure will be apparent to the person skilled in the art.
Two examples of gel compositions according to the present disclosure are given in Table 1 below. The amounts given are as the raw material ingredient used to make the composition. Unless otherwise stated the ingredients were used as 100% active ingredients.
The gel compositions were translucent. They were made by the particular method described hereinabove using premix A and premix B which are mixed together, with the potassium hydroxide, and the potassium thioglycolate added to this mixture. Finally, the aminomethylpropanol was added to produce the gel composition.
The results obtained with Examples 1 and 2 are given in Table 2.
Example 1 was tested for hair removal efficacy by the following test:
As a comparison against Example 1, a commercially available hair removal product (NAIR® Glide on Depilatory product, having a pH at 20° C. of around 12.5) was also tested by the same method as above. The results are given in Table 3.
The compositions of the present disclosure are well tolerated by the skin yet provide effective hair removal in an acceptable contact time with the hair to be removed, even though the pH of the compositions is relatively low compared to typical depilatory compositions comprising depilatory actives such as the Nair® Glide on Depilatory product. They also exhibit good pH stability on storage.
A cream formulation according to the present disclosure was prepared according to the formulation in Table 4. The composition was made by the following method and had a pH at 20° C. of 10.5.
The following depilatory compositions in Table 5 were prepared by the method detailed below.
Examples 4a and 4b comprise aminomethylpropanol and are according to the present disclosure. Example 4c is a comparative example which comprises TRIS (tris(hydroxymethyl)aminomethane) and Example 4d is a comparative example which comprises TEA (triethanolamine).
The first AMP containing composition (Example 4a) contained 10.00 wt % of the TGK solution to match the amount of TGK present in the comparative examples 4c and 4d. The second AMP containing composition (Example 4b) contained 12.90 wt % of the TGK solution to match the typical level of depilatory active commonly used in depilatory creams for normal skin types.
The above compositions were tested to assess their hair removal efficacy following the test method given above. The hair removal results are given in Table 6 below.
The above hair removal results demonstrate the advantages of including AMP in the depilatory compositions as the compositions of examples 4a and 4b demonstrate significantly higher percentage hair removal than the compositions of examples 4c or 4d which do not contain AMP but instead contain other amine-based ingredients.
Example 4a comprising AMP, example 4c comprising TRIS and example 4d comprising TEA were tested for their hair removal efficacy, using the above method, after preparation. The examples were then stored at room temperature for a period of 3 months. At 1-month and 2-month storage times, a sample of the stored example was removed and tested for hair removal efficacy using an in-vitro hair removal test model. The examples were also tested at the end of their 3-month storage period. The results of the hair removal testing are given below in Table 7.
The in-vitro test method used was:
The above results demonstrate that the AMP containing compositions of the present disclosure still provide the highest percentage of hair removal even after being stored for 3 months. This is believed to be related to the pH stability of the compositions according to the present disclosure.
Examples 4a and 4b, which are examples according to the present disclosure, gave hair removal results of 93.21% and 94.93% respectively when tested as in Example 4 (see table 5). These compositions had a pH of 10.8 and 10.75 at 20° C. The compositions provided for good hair removal results and were well tolerated by the skin.
A comparative, commercially, available depilatory composition Veet Depilatory Cream (normal skin type) which is not according to the present disclosure (as it does not contain AMP) was also tested according to the method given above to determine its hair removal properties. This composition had a pH of 12.6 at 20° C. The composition exhibited a hair removal result of 97.6%.
The hair removal results achieved for Examples 4a and 4b and the commercial, comparative formulation are similar. However, the lower pH of Examples 4a and 4b is considered to be desirable (but not by way of limitation) for a depilatory composition, as there is understood to be a reduced likelihood of damage to the skin during or after usage of the product, particularly if the usage instructions are not correctly followed and the product is left in contact with the skin for longer than the recommended treatment time.
Gel compositions according to the present disclosure were prepared according to the formulations given in Table 8. Compositions 7a and 7b were prepared by the method given for Example 4. For compositions 7c and 7d comprising the PVM/MA Decadiene crosspolymer, the following method was used to produce the compositions.
The compositions of Examples 7a to 7d were tested to determine their efficacy for hair removal by following the method given hereinabove. The results of the hair testing are shown in the Table 9 below:
From the above results it can be seen that the Carbopol gelling agent gives better hair removal results (for a given percentage of urea in the formulation) than does the PVM/MA Decadiene crosspolymer (Stabilize) gelling agent. Therefore, Carbopols are particular (but non-limiting) gelling agents according to the present disclosure, and a particular (but non-limiting) embodiment of the compositions comprises Carbopol, urea, and xanthan gums.
The PVM/MA Decadiene crosspolymer (Stabileze) gelling agent provides acceptable levels of hair removal provided that a sufficient amount of urea is also included in the composition. The amount of urea required for the Stabileze compositions to obtain a highly effective depilatory composition has been found to be higher than for an equivalent Carbopol containing formulation.
It can also be seen from the above results that the formulations containing Carbopol, urea and xanthan gum (7a and 7b) provide for more effective hair removal than their equivalent formulations containing PVM/MA Decadiene crosspolymer (Stabileze) and urea (7c and 7d) even though the Carbopol, urea and xanthan gum containing formulations contain less depilatory active (TGK) and aminomethylpropanol). This demonstrates that the combination of Carbopol, urea and Xanthan gum allows for a reduction in the amount of depilatory active and aminomethylpropanol used in the compositions whilst still achieving enhanced hair removal results compared to the compositions comprising PVM/MA Decadiene crosspolymer (Stabileze) and urea.
Gel compositions according to the present disclosure were prepared according to the formulations given in Table 10. The compositions were prepared by the method below.
The Ceteareth 20 used was Emulgin B2 ex BASF, a 100% active ingredient.
The Cetearyl alcohol used was Lanette S3 Past ex BASF, a 100% active ingredient.
The compositions of Examples 8a and 8b were tested to determine their efficacy for hair removal by following the method given hereinabove. The results of the hair testing are shown in Table 11 below:
The above results demonstrate that the Laponite-containing composition provides for acceptable hair removal but the carbopol-containing composition provides for a greater degree of hair removal. Particular non-limiting embodiments of the compositions of the present disclosure comprise carbopol.
The compositions in Table 12 were produced according to the method given above for Example 8 except that no AMP is included in the compositions.
The compositions of Examples 9a and 9b were tested to determine their efficacy for hair removal by following the method given for Example 8. The results of the hair testing are shown in Table 13 below:
The above results demonstrate that the combination of the Carbopol, urea and xanthan gum provides a greater degree of hair removal than the combination of the Lithium Magnesium Sodium Silicate, urea and xanthan gum even in the absence of AMP.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1600586.0 | Jan 2016 | GB | national |
This application is a continuation of U.S. patent application Ser. No. 17/685,732, filed 3 Mar. 2022; which is a continuation of U.S. patent application Ser. No. 16/069,692, filed 12 Jul. 2018, now U.S. Pat. No. 11,266,586, issued 8 Mar. 2022; which is a US National Phase of International Patent Application No. PCT/GB2017/050077, filed on 12 Jan. 2017; which claims priority to United Kingdom Application Serial No. 1600586.0, filed 12 Jan. 2016. The entire contents of each of these patent applications are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17685732 | Mar 2022 | US |
| Child | 19027353 | US | |
| Parent | 16069692 | Jul 2018 | US |
| Child | 17685732 | US |
