WO2019110290A1

WO2019110290A1 - An antiperspirant composition comprising zirconium

Info

Publication number: WO2019110290A1
Application number: PCT/EP2018/081869
Authority: WO
Inventors: Xiaoke Li; Renjiang LIU; Philip Christopher Waterfield; Huanjun ZHOU
Original assignee: Unilever NV; Conopco Inc
Current assignee: Unilever NV; Conopco Inc
Priority date: 2017-12-04
Filing date: 2018-11-20
Publication date: 2019-06-13
Anticipated expiration: 2020-06-04

Abstract

The present invention is in the field of antiperspirant compositions, in particular compositions comprising antiperspirant actives. The present invention more particularly relates to compositions comprising zirconium based anti-perspirant actives which are stable before use and effective in ensuring anti-perspirant benefits. This is achieved through formulating the anti-perspirant active in a cosmetically acceptable base.

Description

AN ANTIPERSP!RANT COMPOSITION COMPRISING ZIRCONIUM

Field of the invention

The present invention is in the field of antiperspirant compositions. The present invention more particularly relates to compositions comprising a zirconium based antiperspirant active which is effective in ensuring anti-perspirant benefits.

Background or the invention

The present invention relates to compositions, such as those that contain antiperspirant actives. These actives are added to compositions to reduce perspiration on application to the surface of the body, particularly to the underarm regions of the human body viz. the axilia. Antiperspirant actives are typically astringent metal salts such as those of aluminium or zirconium. However conventional aluminium or zirconium salts have certain disadvantages. In particular, it may cause local skin irritation. Antiperspirant actives are usually incorporated in compositions at low pH, in the range of 2 to 7.

US4650671A (Claus Riemann 4 Co. ApS, 1984) discloses a method for controlling perspiration, and kit for carrying out that method. The method involves the separate, sequential application of an AICI3- or ZrCI4- containing antiperspirant composition and a physiologically tolerable basic buffer-containing composition. Separate, successive application of the antiperspirant and the buffer prevents skin irritation or damage to the user's clothes attributable to acid formed from the antiperspirant, and provides antiperspirant activity.

US3407254 (Bernard Siegal et al, 1968) discloses an antiperspirant composition comprising an aqueous carrier and a zirconium complex having specific structure.

Preferably the composition has a pH in the range of about 0.5 to 3.5.

The present inventors have tested the zirconium salts proposed in the past for anti- perspirancy benefits and discovered that they suffer either from being unstable when formulated or cause local skin irritation because of the hydrolysis of zirconium salts. It is desired that the antiperspirant active does not degrade when formulated and stored for periods of time (sometimes up to several months) before they are used by the consumer. When the formulated product is applied to the skin it is desired that the antiperspirant active can deliver antiperspirant benefit by forming particles with the biomolecules in the sweat pores such that it can clog or gel in the sweat pores and inhibit further sweating. The present inventors then found out that this problem can be solved by formulating a specific zirconium complex in a cosmetically acceptable carrier.

It is thus an object of the present invention to provide for an antiperspirant composition which exhibits sustained antiperspirant efficacy from zirconium based actives.

Summary of the invention

According to the first aspect of the present invention there is provided an antiperspirant composition comprising

(i) a zirconium complex wherein zirconium is chelated with alkanolamine; and

(ii) a cosmetically acceptable carrier.

wherein the zirconium complex is tetrakis[[2,2’,2”-nitri!otris[ethanolato]](1-)- M.Ojzirconium (CAS number: 101033-44-7) having the following structure:

[Formula 1]

According to another aspect of the present invention there is provided a non- .

therapeutic method of reducing perspiration comprising the step of applying a composition as claimed in the first aspect on to the desired skin surface.

According to another aspect of the present invention there is provided non-therapeutic use of a zirconium compound chelated by alkanolamine for reduction of sweat or for use as an antiperspirant active. Detailed description of the invention

These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word“comprising” is intended to mean“including” but not necessarily "consisting of or“composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word “about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

The compositions of the invention are typically "personal care compositions”, suitable for cosmetic use as detailed below. Further, use of the compositions of the invention is typically cosmetic, non-therapeutic use.

In some embodiments of the present invention, the compositions may be used for the therapeutic treatment of hyperhidrosis (extreme sweating). In one aspect the compositions of the invention are used for therapeutic treatment. Alternatively, the compositions are used for non-therapeutic applications, more particularly for cosmetic purposes.

By“An Antiperspirant Composition” as used herein, is meant to include a composition for topical application to the skin of mammals, especially humans. Such a composition is preferably of the leave-on type. By a leave-on composition is meant a composition that is applied to the desired skin surface and left on for a period of time (say from one minute to 24 hours) after which it may be wiped or rinsed off with water, usually during the regular course of personal washing. The composition may also be formulated into a product which is applied to a human body for improving the appearance, cleansing, odor control or general aesthetics. The composition of the present invention can be in the form of a liquid, lotion, cream, foam, scrub, gel or stick form and may be delivered through a roll-on device or using a propellant containing aerosol can. It is especially useful for delivering low pH compositions to the axilla of an individual for anti- perspirancy benefits. "Skin” as used herein is meant to include skin on any part of the body (e.g., neck, chest, back, arms, underarms, hands legs, buttocks and scalp) especially the underarms.

The present invention is directed to delivering a zirconium based antiperspirant active on to the topical surface of a human body. The active for inclusion in the composition is a zirconium complex where the zirconium is chelated by alkanolamine.

The zirconium complex in accordance with this invention is tetrakis[[2,2’,2”- nitrilotris[ethanolato]](1-)-N,0]zirconium (CAS number: 101033-44-7) having the following structure:

[Formula 1]

Tetrakis[[2,2\2”-nitrilotris[ethanolato]](1-)-N,0]zirconium (having CAS number: 101033- 44-7) is the zirconium aikanolamine chelated complex, as per this invention

(compound of formula 1). Two of the Major suppliers are Dorf Ketal and Catalytic Technologies Limited. The preferred zirconium triethanolate actives are available with the brand name TYZOR TEAZ from Dorf Ketal supplier and IG825 from Catalytic Technologies Limited. It is mainly used in the petroleum refining industry. The above zirconium alkanolamine complex is preferably included in 0.5 to 30%, more preferably 1 to 15%, furthermore preferably 3 to 10% by weight of the composition

Antiperspirant compositions of the present invention may advantageously comprise an additional antiperspirant active. Whilst this might be a conventional antiperspirant salt comprising Al and/or Zr, such as aluminium chlorohydrate or aluminium-zirconium chlorohydrate optionally complexed with glycine, it is preferred that any additional antiperspirant active is not of this type.

Other components commonly included in conventional antiperspirant compositions may also be incorporated in the compositions of the present invention. Such components include skin care agents such emollients, humectants and skin barrier promoters; skin appearance modifiers such as skin lightening agents and skin smoothing agents; anti- microbial agents, in particular organic anti-microbial agents, and preservatives.

The anti-perspirant active can be applied cosmetically and topically to the skin, broadly speaking, by one of two methods. Different consumers prefer one method or the other. In one method, sometimes called a contact method, a composition is wiped across the surface of the skin, depositing a fraction of the composition as it passes. In the second method, sometimes called the non-contact method, the composition is sprayed from a dispenser held proximate to the skin, often in an area of about 10 to 20 cm². The spray can be developed by mechanical means of generating pressure on the contents of the dispenser, such as a pump or a squeezable sidewall or by internally generated pressure arising from a fraction of a liquefied propellant volatilising, the dispenser commonly being called an aerosol.

There are broadly speaking two classes of contact compositions, one of which is liquid and usually applied using a roll-on dispenser or possibly absorbed into or onto a wipe, and in the second of which the antiperspirant active is distributed within a carrier liquid that forms a continuous phase that has been gelled. In one variation, the carrier fluid comprises a solvent for the antiperspirant and in a second variation, the antiperspirant remains a particulate solid that is suspended in an oil, usually a blend of oils. Stick or soft solid compositions

Many different materials have been proposed as gellant for a continuous oil phase, including waxes, small molecule gelling agents and polymers. They each have their advantages and of them, one of the most popular class of gellant has comprised waxes, partly at least due to their ready availability and ease of processing, including in particular linear fatty alcohol wax gellants, A gelled antiperspirant composition is applied topically to skin by wiping it across and in contact with the skin, thereby depositing on the skin a thin film.

The nature of the film depends to a significant extent on the gellant that is employed. Although wax fatty alcohols have been employed as gellant for many years, and are effective for the purpose of gelling, the resultant product is rather ineffective at improving the visual appearance of skin, and in particular underarm skin, to which the composition has been applied. This problem has been solved by including

ameliorating materials for example, di or polyhydric humectants and/or a triglyceride oil.

Roll-on

Liquid compositions that are applicable from a roll-on broadly speaking can be divided into two classes, namely those in which an antiperspirant active is suspended in a hydrophobic carrier, such as a volatile silicone and those in which the antiperspirant active is dissolved in a carrier liquid. The latter has proven to be more popular. There are mainly two sorts of dissolving carrier liquid, namely carriers that are predominantly alcoholic, which is to say the greater part of the dissolving carrier fluid comprises ethanol and the second class in which the carrier liquid is mainly water. The former was very popular because ethanol is a mild bactericide in its own right, but its popularity waned because it stings, especially if the surface onto which the composition has been applied has been damaged or cut, such as can easily arise during shaving or other de-hairing operations.

The second class of formulations that is an alternative to alcoholic formulations comprise a dispersion of water-insoluble or very poorly water soluble ingredients in an aqueous solution of the antiperspirant. Herein, such compositions will be called emulsions, Antiperspirant roll-on emulsions commonly comprise one or more emulsifiers to maintain a distribution of the water-soluble ingredients.

Aerosol compositions

The antiperspirant composition may be delivered through an aerosol composition which comprises a propellant in addition to the other ingredients described hereinabove. Commonly, the propellant is employed in a weight ratio to the base formulation of from 95:5 to 5:95. Depending on the propellant, in such aerosol compositions the ratio of propellant to base formulation is normally at least 20:80, generally at least 30:70, particularly at least 40:60, and in many formulations, the weight ratio is from 90:10 to 50:50. A ratio range of from 70:30 to 90:10 is sometimes preferred.

Propellants herein generally are one of three classes; i) low boiling point gasses liquefied by compression, ii) volatile ethers and iii) compressed non-oxidising gases.

Class i) is conveniently a low boiling point material, typically boiling below -5°C, and often below -15°C, and in particular, alkanes and/or halogenated hydrocarbons. This class of propellant is usually liquefied at the pressure in the aerosol canister and evaporates to generate the pressure to expel the composition out of the canister.

Examples of suitable alkanes include particularly propane, butane or isobutane, The second class of propellant comprises a very volatile ether of which the most widely employed ether hitherto is dimethyl ether. This propellant can advantageously be employed at relatively low weight ratio of propellant to base formulation, for example to as low as 5:95. It can also be employed in admixture with, for example,

compressible/liquefiable alkane gasses. The third class of propellant comprises compressed non-oxidising gasses, and in particular carbon dioxide or nitrogen. Inert gases like neon are a theoretical alternative.

When the composition of the invention is delivered in a roll-on, a firm solid or a stick format, the topically acceptable carrier comprises an anhydrous carrier or an aqueous carrier. The anhydrous carrier in such cases may comprise a silicone compound, low boiling alcohol or a wax. When the composition comprises a propellant it is delivered as an aerosol.

The composition of the present invention can comprise a wide range of other optional components. The CTFA Personal Care Ingredient Handbook, Second Edition, 1992, which is incorporated by reference herein in its entirety, describes a wide variety of non-limiting personal care and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention. Examples include: antioxidants, binders, biological additives, buffering agents, colorants, thickeners, polymers, astringents, fragrance, conditioners, exfoliating agents, pH adjusters, preservatives, natural extracts, essential oils, skin sensates, skin soothing agents, and skin healing agents.

A preservative is a preferred additional component in compositions of the invention. A preservative serves to reduce or eliminate microbial contamination of compositions of the invention. Preservatives are typically employed at a total level of from 0.05 to 3%, preferably at from 0.1 to 2% and most preferably at from 0.4 to 1%.

Suitable preservatives for use with the present invention include 2-phenoxyethanol, iodopropynyl butylcarbamate, C1-C3 alkyl parabens, sodium benzoate, caprylyl glycol and EDTA. Particularly preferred preservatives are 2-phenoxyethanol, iodopropynyl butylcarbamate, sodium benzoate, caprylyl glycol and EDTA and especially preferred are 2-phenoxyethanol and iodopropynyl butylcarbamate.

A preferred additional component of compositions of the invention is a fragrance.

Suitable materials include conventional perfumes, such as perfume oils and also include so-called deo-perfumes, as described in EP 545,556 and other publications. Levels of incorporation are preferably up to 4% by weight, particularly from 0.1% to 2% by weight, and especially from 0.7% to 1.7% by weight.

An antimicrobial deodorant active is a preferred an additional component in

compositions of the invention. Such components serve to reduce or eliminate body odour by reducing or otherwise impeding the function of microbes on the skin of the body responsible for malodour generation.

The antimicrobial deodorant active may also be a preservative for the composition.

When employed, the anti-microbial deodorant agent is typically incorporated into the composition at from 0.01% to 3% and particularly at from 0.03% to 0.5%.

Preferred anti-microbial deodorant agents have a minimum inhibitory concentration (MIC) of 1 mg. ml ¹ or less, particularly 200 pg.mh¹ or less, and especially 100 pg.ml ¹ or less. The MIC of an anti-microbial agent is the minimum concentration of the agent required to significantly inhibit microbial growth. Inhibition is considered“significant” if an 80% or greater reduction in the growth of an inoculum of Staphylococcus epidermidis is observed, relative to a control medium without an anti-microbial agent, over a period of 16 to 24 hours at 37°C. Details of suitable methods for determining MIGs can be found in“Antimicrobial Agents and Susceptibility Testing”, C.Thornsberry, (in“Manual of Clinical Microbiology”, 5^th Edition, Ed. A. Balows et al, American Society for Microbiology, Washington D.C., 1991). A particularly suitable method is the Macrobroth Dilution Method as described in Chapter 110 of above publication (pp. 1101-1 111) by D. F. Sahm and J. A. Washington II. MlCs of anti-microbials suitable for inclusion in the compositions of the invention are triclosan: 0.01 -10 pg.ml^-1 (J.Regos et al , Dermatologies (1979), 158: 72-79) and farnesol: ca. 25 pg.mH (K, Sawano, T.

Sato, and R. Hattori, Proceedings of the 17^th IFSCC International Conference,

Yokahama (1992) p.210-232). By contrast ethanol and similar alkanols have MlCs of greater than 1 mg. ml ¹.

Suitable organic anti-microbials are bactericides, for example quaternary ammonium compounds, like cety!trimethylammonium salts; chlorhexidine and salts thereof; and diglycerol monocaprate, diglycerol monolaurate, glycerol monolaurate, and similar materials, as described in "Deodorant Ingredients”, S.A.Makin and M.R.Lowry, in “Antiperspirants and Deodorants", Ed, K. Laden (1999, Marcel Dekker, New York).

More preferred anti-microbials for use in the compositions of the invention are polyhexamethylene biguanide salts (also known as polyaminopropyl biguanide salts), an example being Cosmocil CQ™ available from Zeneca PLC, preferably used at up to

1% and more preferably at 0.03% to 0.3% by weight; ZAA-trichioro^-hydroxy- diphenyl ether (triclosan), preferably used at up to 1 % by weight of the composition and more preferably at 0.05-0.3%; and 3,7,11 -trimethyldodeca-2,6, 10-trienol (farnesol), preferably used at up to 1 % by weight of the composition and more preferably at up to 0.5%.

Other suitable organic antimicrobial agents are transition metal chelators, as described in W001/52805, for example. Transitional metal chelators having a binding coefficient for iron(lll) of greater than 10²⁶, for example diethylenetriaminepentaacetic acid and salts thereof are preferred.

The present invention also provides for a method of reducing perspiration comprising the step of applying the composition of the first aspect on to the desired skin surface. The skin surface could be any topical surface which is prone to sweating especially the axilla i.e. the underarm portion of the human body. The method is preferably non- therapeutic. The invention also provides for use of the zirconium complex where zirconium is chelated by alkanolamine, for manufacture of a composition as claimed in the present invention, for reduction of sweat.

The invention also provides for use of a zirconium complex wherein zirconium is chelated by alkanolamine as an antiperspirant active. The use is for therapeutic treatment. Alternatively, the use is for non-therapeutic purposes, particularly for cosmetic purposes.

The invention will now be demonstrated with the help of the following non-limiting examples. Examples

Materials

Examples 1-9: Stability of compositions at 45 °C over four weeks storage:

The following compositions were prepared as given in Table 1.

Table 1

The above compositions were tested for stability by using the following procedure:

The samples were transferred into transparent plastic jars which were then stored at 45

°C for 4 weeks. The appearance of each of the samples was checked visually and recorded at various time points. The samples were graded as either Transparent (T), Cloudy (C) or Precipitate (P). The data on the appearance of the samples is summarized in Table - 2 below: Table 2

The data in Table 2 above indicates that compositions as per the invention (Examples 1- 9) were stable on storage for up to 4 weeks.

Examples 10 to 12: Gelation of the compositions in the presence of guar polymer

It is desirable that the compositions could cross-link the polysaccharide in sweat duct and then form a gel. The cross-linked polysaccharide which forms the gel in the sweat ducts would thereby act as antiperspirants.

The following experiment was used to check the polysaccharide crosslink ability of Zirconium compounds. It is believed that mucin in the sweat duct which is a family of glycosylated proteins have glycosyls similar as polysaccharide. Therefore, if the zirconium complex can crosslink the polysaccharide, it indicates that the zirconium complex can crosslink mucin in the sweat duct. Three Zirconium compounds were tested in this study, which were Tyzor 212, Tyzor 210 and IG 825. Guar polymer is used here as a kind of polysaccharide which is commonly used in cosmetic compositions.

10ml Zirconium compound water solutions were prepared by dissolving 3ml Zirconium compound into 7tni distilled water. 2% Guar polymer solution was mixed with the Zirconium compound water solutions with 1 : 1 ratio in transparent plastic tubes which were then stored at room temperature (25 °C). The appearance of each of the samples was checked visually and recorded. The compositions as per the invention (Examples

10-12) are seen to gradually form a gel in 3min as showed in T able - 3 below.

Table 3

Note: G indicates gelation was observed

Examples 13. Flocculation of the compositions in the presence of BSA ft was believed that the interaction and formation of floe between biomolecules and metal compound in sweat duct could contribute anti-perspirant efficacy.

The following procedure was used to check the effect of Zirconium compounds precipitating Bovine serum albumin (BSA).

1% BSA solution was prepared by dissolving BSA in distilled water. Then, 1g Tyzor212 (Example 13) was added into 10ml BSA solution. It was observed that the solution became turbid immediately after mixing Tyzor212 with 1%BSA solution.

Examples 14 to 16: Gelation of different zirconium complex in the presence of guar polymer.

An antiperspirant composition comprising a zirconium complex as given in Table 4 was prepared according to the description set forth in Example 7 of US Patent No.3407254. The pH of the composition was 3.4 Table 4

The following compositions were prepared as given in Table 5.

Table 5

2% guar polymer solution was mixed with each of the samples (Example A, 14 to 16) at 1 :1 weight ratio in transparent plastic tubes which were then stored at room

temperature (25 °C). The appearance of each of the samples was checked visually and recorded over a period. The result is summarized in Table - 6 below.

Table 6

Note: C indicates clear solution; F indicates flocculation was observed; G indicates gelation was observed.

The data in Table 6 indicates that compositions as per the invention (Examples 14 to 15) at different pH were able to crosslink with the polysaccharide (representing mucin in sweat ducts) and then form a gel to thereby act as antiperspirants, while the other zirconium complex with different structure (Example A) could not form the gel.

Claims

1. An antiperspirant composition comprising:

(i) a zirconium complex wherein zirconium is chelated with alkanolamine; and,

(ii) a cosmetically acceptable carrier.

wherein the zirconium complex is tetrakis[[2 2',2’'-nitrilotris[ethanolato]](1-)- IM,0]zircomum (CAS number: 101033-44-7) having the following structure:

[Formula 1]

2. A composition as claimed in claim 1 wherein the pH of the composition is from 3 to 7.

3. A composition as claimed in claim 1 or 2 wherein the zirconium complex is included in 1 to 30% by weight of the composition.

4. A composition as claimed in any one of claims 1 to 3 wherein the cosmetically acceptable carrier comprises an anhydrous carrier or an aqueous carrier.

5. A composition as claimed in claim 4 wherein the anhydrous carrier comprises a silicone compound, low boiling alcohol or a wax.

6. A composition as claimed in claim 4 or 5 which is delivered as a roll-on, a firm solid or a stick.

7. A composition as claimed in any of claims 1 to 3 wherein the cosmetically

acceptable carrier comprises a propellant and the composition is delivered as an aerosol.

8. A composition according to any of preceding claims comprising a fragrance.

9. A composition according to any of preceding claims comprising an antimicrobial deodorant.

10. A composition according to any of preceding claims comprising a preservative.

11. A non-therapeutic method of reducing perspiration comprising the step of

applying a composition as claimed in any one of claims 1 to 10 on to the desired skin surface.

12. Non-therapeutic use of a zirconium complex wherein zirconium is chelated with alkanolamine for reduction of sweat.