Deodorant compositions

Abstract

A deodorant stick composition comprising (i) a glycol selected from propylene glycol (PG) and / or dipropylene glycol (DPG); (ii) water; (iii) a structurant; and (iv) polylysine.

Description

[0001] Deodorant Compositions

[0002] Field of Invention

[0003] The invention is concerned with deodorant stick compositions, particularly such compositions having enhanced deodorancy activity.

[0004] There are numerous references to the use of polypeptides comprising lysine in cosmetic compositions in the prior art, but relatively few relate to deodorant compositions.

[0005] DE 102014222 023 A1 (Henkel, 2016) discloses aluminium free antiperspirant compositions comprising a gamma-aminobutyric acid or similar amino acid and a broadly defined “design protein”.

[0006] WO 2012 / 168360 A2 (BDF, 2012) discloses active substance combinations comprising epsilon-polylysine, piroctone olamine and / or climbazole.

[0007] US 2017 / 157017 (Henkel, 2017) discloses antiperspirant compositions comprising a design protein and which are exempt of aluminium and / or zirconium antiperspirant actives. Preferred design proteins are selected from polylysine, polyarginine, polyglutamine, polyhistidine, polyproline, as well as mixtures thereof.

[0008] DE 102014216893 A1 (Henkel, 2016) discloses the use of at least one specific protein to reduce the amount of antiperspirant compound needed in an antiperspirant composition.

[0009] JP2004035461 A2 (Chisso Corp., 2004) discloses deodorant compositions comprising epsilon-polylysine which operates as an antibacterial agent and thereby reduces malodour. of Invention

[0010] The invention is concerned with deodorant stick compositions have excellent effectiveness at reducing malodour on the surface of the human body. The deodorant compositions involved comprise a synergistic blend of glycols and polylysine.

[0011] It is an object of the invention to provide deodorant stick compositions having superior efficacy.

[0012] It is a further object of the invention to provide emulsion deodorant compositions that have good sensory properties.

[0013] It is a further object of the invention to provide deodorant stick compositions that have good stability.

[0014] In a first aspect of the invention, there is provided a deodorant stick composition comprising (i) a glycol selected from propylene glycol (PG) and / or dipropylene glycol (DPG); (ii) water; (iii) a structurant; and (iv) polylysine.

[0015] In a second aspect of the invention, there is provided a method of manufacture of a deodorant composition according to the first aspect of the invention.

[0016] In a third aspect of the invention, there is provided a cosmetic method of obtaining a deodorancy benefit comprising the topical application to the surface of the human body of a deodorant composition according to the first aspect of the invention.

[0017] In a fourth aspect of the present invention, there is provided the use of polylysine to enhance the deodorancy performance of a deodorant stick according to the first aspect of the invention. Detailed

[0018] Herein, features expressed as “preferred” with regard to a particular aspect of the invention should be understood to be preferred with regard to each aspect of the invention (likewise, features expressed as “more preferred”, “particularly preferred” or “most preferred”). “Preferred” features aid the delivery of one or more of the objects of the invention.

[0019] Herein, preferred features of the invention are particularly preferred when used in combination with other preferred features (likewise, features expressed as “more preferred”, “particularly preferred” or “most preferred”).

[0020] Herein, “ambient conditions” refer to 20°C and 1 atmosphere pressure, unless otherwise indicated.

[0021] Herein, water-soluble refers to materials having a solubility in water of at least 10 g / l, such as from 10 g / l to 500 g / l, under ambient conditions.

[0022] Herein, all percentages, ratios and amounts are by weight, unless otherwise indicated.

[0023] Herein, amounts and concentrations of ingredients are percentages by weight of the total composition, unless otherwise indicated.

[0024] Herein, references to amounts of components such as “oil” or “structurant” relate to the total amount of such components present in the composition.

[0025] Herein, the word “comprising” is intended to mean “including” but not necessarily “consisting of”, i.e. , it is non-exhaustive.

[0026] Herein, “cosmetic” methods and compositions should be understood to mean non- therapeutic methods and compositions, respectively.

[0027] The deodorant stick compositions of the present invention preferably have a hardness of less than 20 mm, more preferably less than 15 mm and most preferably less than 12 mm. Such sticks can demonstrate a combination of aesthetically desirable properties, including sensory benefits such as the avoidance of excessive drag on application and sometimes lower visible marks on clothing worn in close proximity to the area of application on the skin.

[0028] Herein, the “hardness” of the stick composition refers to the depth, in millimetres, that a cone penetrates into a test specimen under fixed conditions, as determined in accordance with the procedures of ASTM Method D217-48, incorporated herein by reference, using a Petrotest PNR10 Penetrometer (or equivalent), equipped with an ASTMD2884 plunger (Petrotest Cat. #18-0081 or equivalent, weight =47.5 g) and a 2.5 g aluminium cone, 20° angle with a base diameter of 10 mm, wherein hardness values are reported as an average of 6 replicate measurements.

[0029] Deodorant sticks of the present invention preferably have a pH of at least 8 and more preferably from 8 to 11. These pH values can aid the deodorancy properties of the stick.

[0030] Herein, propylene glycol, often abbreviated to PG, is the chiral molecule propane-1 , 2-diol, having the molecular formula CH3CH(OH)CH2OH. It is typically used as the racemate. Propane-1 , 3-diol, frequently called just “propanediol”, is a different material.

[0031] The PG content of compositions of the invention is preferably from 10 to 70%, more preferably from 10 to 50% and most preferably from 15 to 30%.

[0032] Herein dipropylene glycol, often abbreviated to DPG, refers to one or more of the isomers typically comprising this commercially available raw material. The isomers have the formula C6H14O3, and each have two hydroxy groups and one oxa (-O-) link. Typically, a mixture of the isomers as sold commercially is employed. DPG of molecular formula CH3CH(OH)CH2OCH2CH(OH)CH3 and having the IIIPAC name 4-oxa-2,6-heptandiol is generally present in the mixture employed. Other isomers typically present are 2-(2- hydroxy-propoxy)-propan-1-ol and 2-(2-hydroxy-1-methyl-ethoxy)-propan-1-ol.

[0033] The DPG content of compositions of the invention is preferably from 20 to 70%, more preferably from 30 to 50% and most preferably from 35 to 45%. The ratio of PG to DPG in compositions according to the invention is preferably from 1 : 5 to 1 : 1, more preferably from 1 : 3 to 1 : 1 and most preferably from 1 : 1 to 1 : 2.

[0034] The structurant is responsible for converting the liquid components of the composition into a solid stick.

[0035] Preferred structurants are sodium salts of a fatty acid having from 16 to 20 carbon atoms. Particularly preferred are sodium salts of linear fatty acids having from 16 to 20 carbon atoms and especially preferred are sodium salts of linear saturated fatty acids having from 16 to 20 carbon atoms. The most preferred structurant is sodium stearate.

[0036] The structurant is preferably present in sufficient quantity to give the stick a hardness of less than 20 mm, more preferably less than 15 mm and most preferably less than 10 mm. Hardness is measured using the method previous described (vide supra).

[0037] The amount of the structurant used in stick compositions of the invention is preferably from 3%, more preferably from 4% and most preferably from 5%. The upper amount is preferably up to 25%, more preferably up to 15% and most preferably up to 8%. The preferred ranges of structurant may be selected from any of the lower and upper amounts indicated in this paragraph.

[0038] Herein, polylysine is to be understood to be a polypeptide comprising predominantly lysine residues, preferably linked through the amino group epsilon to the carboxylic acid. Such polylysines are referred to as epsilon polylysine or poly-epsilon-lysine.

[0039] Typically, the lysine residues are naturally occurring L-lysine.

[0040] The term “predominantly” when used with reference to polylysine means that greater than 50% of the amino acid residues present in the polypeptide are lysine, more preferably this figure is greater than 75%, and even more preferably greater than 90%. In this paragraph, the percentages referred to are by number, rather than by weight.

[0041] Most preferably, the polylysine is a homopolymer. The polylysine is preferably not cationic in compositions of the invention in order to aid its incorporation into the stick; however, the polylysine becomes cationic on application to the skin, which typically has a lower pH, thereby aiding its antimicrobial and deodorancy properties.

[0042] The polylysine preferably comprises at least 15 lysine residues, more preferably at least 20 residues and most preferably from 25 to 30 residues.

[0043] With reference to molecular weight, preferred polylysines have an Mw of from 3000 to 5000 and an Mn of from 3700 to 5700. The polydispersity of the polylysine is preferably from 1.0 to 1.3.

[0044] A preferred oil for use in compositions prepared in accordance with the invention is a fragrance oil, sometimes alternatively called a perfume oil. The fragrance oil may comprise a single fragrance or component more commonly a plurality of fragrance components. Herein, fragrance oils impart an odour, preferably a pleasant odour, to the composition. Preferably, the fragrance oil also imparts a pleasant odour to the surface of the human body to which the composition is applied.

[0045] The amount of fragrance oil in the composition is commonly up to 3% advantageously is at least 0.5% and particularly from 0.8% to 2%.

[0046] Preferably compositions of the invention are free from silicone oil, in particular volatile silicone oil.

[0047] Herein, a volatile silicone oil is one having a vapour pressure of greater than 1 Pa at 25°C, in particular from 1 to 3 Pa.

[0048] A preferred additional component of compositions of the invention is an amino-alcohol. Preferred amino-alcohols are aminomethyl propanol, tetrahydroxypropyl-ethylenediamine, and tris-amino, aminomethyl-propanediol. A particularly preferred amino-alcohol is aminomethyl propanol. Such amino-alcohols enhance the clarity of the composition and may also, surprisingly, contribute to its efficacy as a deodorant. Amino-alcohols, in particular those specified above, are preferably incorporated at a level of from 0.1 to 5%, more preferably from 0.2 to 4% and most preferably from 0.2 to 2%.

[0049] A preferred additional component of compositions of the invention is a vitamin, such as vitamin B (particularly vitamin B3). Vitamins are preferably included at a total level of from 0.1 to 10% and more preferably at from 0.5 to 7.5%.

[0050] Other components that may be included in compositions according to the invention including those described in the following paragraphs.

[0051] Wash-off agents may be included, often in an amount of up to 10%, to assist in the removal of the formulation from skin or clothing. Such wash-off agents are typically nonionic surfactants such as esters or ethers containing a Cs to C22 alkyl moiety and a hydrophilic moiety comprising a polyoxyalkylene group (POE or POP).

[0052] Skin moisturisers, such as glycerol or polyethylene glycol (mol. wt. 200 to 600), particularly glycerol, are preferred additional components. Such polyols, in particular glycerol, are preferably used in an amount of up to 20%, more preferably from 1 to 15% and most preferably from 3 to 10%. Such components enhance the sensory properties of compositions of the invention.

[0053] The composition may comprise one or more of any of the following additional optional ingredients such as: dyes, pigments or colourants; antioxidants such as butylated hydroxytoluene (BHT); surfactants, including nonionic surfactants, such as polymer based nonionic surfactants, for example poloxamine 1307; chelating agents such as disodium EDTA; deodorizing agents; silicones; and, antifoam agents, for example silicone / hydrated silica antifoam agents.

[0054] Compositions of the invention may be manufactured by any of the methods known in the art.

[0055] In a preferred method of manufacture, all of the components of the composition except the polylysine and any fragrance are mixed together under shear at elevated temperature, for example at 75 to 90°C. If fragrance is to be incorporated, this is preferably done after the initial components and after cooling the mixture to less than 75°C. Shortly before or after the fragrance addition, the polylysine is added, again at a temperature of less than 75°C. The fragrance and polylysine are both added under shear to effectively mix these components into the composition. The liquid composition is then poured into stick moulds and allowed to cool to ambient temperature. This results in the composition solidifying into solid sticks.

[0056] The following examples are illustrative of the invention and should not be seen as limiting the scope thereof.

[0057] Examples according to the invention are indicated by number and comparative examples are indicated by letters.

[0058] The following raw materials were used in the examples and comparative examples described below.

[0059] The poly epsilon lysine used was a homopolymer of L-Lysine having the following properties:

[0060] • n = 25-30;

[0061] • Mn = 4090;

[0062] • Mw = 4700;

[0063] • Mw / Mn (polydispersity) = 1.14.

[0064] The Polyquaternium-6 used was a homopolymer of diallyldimethylammonium chloride (DADMAC), known to be an effective cationic antimicrobial agent.

[0065] The Polyquaternium-22 used was a copolymer of diallyldimethylammonium chloride (DADMAC) and acrylic acid, which is also known to be an effective cationic antimicrobial agent. Table 1 - Raw Materials

[0066] The Examples and Comparative Examples indicated in Table 2 were prepared by methods known in the art.

[0067] Table 2 - Compositions

[0068] In a first experiment, the deodorancy performance of Comparative Example A was compared with no treatment in a standard head-to-head test. 41 female panellists took part and dosage applied was 0.29g ± 0.02g.

[0069] 24 hours after application, treatment with Comparative Example A led to a significantly lower odour score than no treatment. The mean malodour scores were 2.134 and 2.518, respectively (p < 0.001). 48 hours after application, Comparative Example A still produced a significantly lower odour score than no treatment. The mean malodour scores were 2.518 and 2.785, respectively (p < 0.001). This result is indicative of the fact that simple PG / DPG sticks do deliver a deodorancy benefit. In a second experiment, the deodorancy performance of Example 1 was compared with that of Comparative Example A in a standard head-to-head test as used in the first experiment. This time, 39 panellists took part and dosage applied was 0.31g ± 0.02g.

[0070] 24 hours after application, treatment with Example 1 led to a significantly lower odour score than treatment with Comparative Example A. The mean malodour scores were 2.234 and 2.386, respectively (p < 0.01). This result is indicative of the fact that addition of polylysine to a simple PG / DPG stick further improves the deodorancy performance.

[0071] In a third experiment, the deodorancy performance of Comparative Example B was compared with that of Comparative Example A in a standard head-to-head test as used in the first experiment. This time, 43 panellists took part and dosage applied was 0.31g ± 0.02g.

[0072] 24 hours after application, treatment with Comparative Example B did not lead to a significantly lower odour score than treatment with Comparative Example A. The mean malodour scores were 1.882 and 1.883, respectively. This result is indicative of the fact that not all cationic antimicrobial agents improve the deodorancy performance of PG / DPG sticks.

[0073] In a fourth experiment, the deodorancy performance of Comparative Example C was compared with that of Comparative Example A in a standard head-to-head test as used in the first experiment. This time, 38 panellists took part and dosage applied was 0.31g ± 0.01g.

[0074] 24 hours after application, treatment with Comparative Example C did not lead to a significantly lower odour score than treatment with Comparative Example A. The mean malodour scores were 2.321 and 2.377, respectively (p = 0.3285). This result is again indicative of the fact that not all cationic antimicrobial agents improve the deodorancy performance of PG / DPG sticks.

Claims

Claims1. A deodorant stick composition comprising (i) a glycol selected from propylene glycol (PG) and / or dipropylene glycol (DPG); (ii) water; (iii) a structurant; and (iv) polylysine.

2. A deodorant stick composition according to claim 1 , wherein the polylysine is epsilon polylysine.

3. A deodorant stick composition according to claim 1 or claim 2, wherein the polylysine is a homopolymer.

4. A deodorant stick composition according to any one of the preceding claims, wherein the polylysine comprises at least 15 lysine residues.

5. A deodorant stick composition according to any one of the preceding claims having a pH of at least 8.

6. A deodorant stick composition according to any one of the preceding claims, comprising both PG and DPG at a weight ratio of from 1 : 5 to 1 : 1.

7. A deodorant stick composition according to any one of the preceding claims, wherein the structurant is the sodium salt of a fatty acid having from 16 to 20 carbon atoms.

8. A deodorant stick composition according to any one of the preceding claims, wherein the structurant is present at level of from 4 to 8% by weight.

9. A deodorant stick composition according to any one of the preceding claims, wherein the stick has a hardness of less than 20 mm.

10. A deodorant stick composition according to any one of the preceding claims, comprising an amino-alcohol.

11. A deodorant stick composition according to claim 10, comprising aminomethyl propanol at a level of from 0.1 to 5% by weight.

12. A deodorant stick composition according to any one of the preceding claims, wherein the polylysine is present at a level of from 0.1 to 2% by weight.

13. A method of manufacture of a deodorant composition according to any one of claims 1 to 11, wherein all of the components of the composition except the polylysine and any fragrance are mixed together under shear at elevated temperature of from 75 to 90°C; following this the composition is cooled to less than 75C and the polylysine and any fragrance are added under shear; the liquid composition is then poured into stick moulds and allowed to cool to ambient temperature to solidify.

14. A cosmetic method of obtaining a deodorancy benefit comprising the topical application to the surface of the human body of a deodorant stick composition according to according to any one of claims 1 to 11.

15. The use of polylysine to enhance the deodorancy performance of a deodorant stick composition according to any one of claims 1 to 11.

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