The present invention relates to an antiperspirant composition.

The object of the present invention is to obtain an antiperspirant composition which gives a real blockade of the function of the sweat glands preferably in the axillae.

In most commercial perspirant inhibiting cosmetics present on the market the active perspirant inhibiting component is usually an adstringent salt of aluminium, zink, zikonum or a rare earth metal. Such salts are as a rule not immediately active as antiperspirants after the first treatement but require a number of treatments during a time period until a desired degree of antiperspiration effect can be obtained. Depending on these problems investigation have been carried out in order to find compounds which have the rapid antiper- spiration effect without requiring a number of trsotments in order to obtain useful antiperspiration effect, which compounds are innocouos to clothes and skin as well. Different anticholinergic compounds have been used, too, which prevent the stimulation of the ecrine sweat-glands by inhibiting the action of acetylcholine.

Further it is previously known as disclosed in Swedish Patent Specification S/N 7200316-3 (publ.no. 381 567) to use 3-phenyl--carbo(β-diethylamino)-ethoxy-2,3-dihydrobensofuran hydrochloride, which is known to possess analgesic, hypotensive, local anesthetic, and antispasmodic effects, as an active component in antiperspirants in amounts of 0.01-2.0% of an aqueous solution.

In Chemical Abstracts 71 (1969), 48238b, it has been disclosed that procaine when administered electrophoretically possesses antihydrotic effect. However, procaine administered without electropheresis but only topical will not give any antihydrotic effect.

It nas now surprisingly been found that it is possible to obtain a rapid and completely effective antiperspiration effect by means of the present invention, which i characterized in that the antiperspirant composition contains at least one local anesthatically active compound of the group prilocaine, benzocaine, lidocaine, bupivacaine, mepivacaine, etidocaine, ketocaine, 2-(2-n-butyloxyphenoxy)-1-diisopropyl- aminoethane, butanilicaine, trimecaine, dibucaine, tetracaine, quinisocaine, butacaine, oxybuprocaine, and tolycaine.

In preferred embodiments of the invention the active substance in the form of its base is used.

The active compounds can, however, form salts, preferably of such a type that is substaintially watersoluble. Such salts are salts with acids, e g hydrohalogen acids, e g hydrobromic acid, hydrochloric acid, hydroiodic acid,and in some cases hydrofluoric acid. Even if the hydrohalogenic acids are prefrred saltforming acids, which are especially useful in connection with the non-substituted compounds, different other wellknown acids able to form salts with amines can be used c g sulohuric acid, sulphuveus acid, acetic acid, phesphoric acid, boric acid, gluconic acid, and carbonic acid. Salts, which are the result of reactions with such acids or of similar saltforming material have usually a higher watersolubility than the original active compounds.

An antiperspirant composition according to the present invention is usually administered as an emulsion containing the anesthetic active agent, an emulsifier, and/or thickening agent and water and when necessary a solvent for the agent.

As suitable emulsifiers Tween® 80, Arlaton® 289, and lecitine can be used.

Arlaton 289 is a polyoxyethylene fatty acid ester, and Tween® 80 is a sorbitansfatty acid ester.

As suitable thickening agent Carbopol , Metocel, Pluronic® and carboxymethylcellulose can be used.

In certain cases the thickening agent may also have emulsifying properties. Thus Carbopol® and Pluronio® can be used both as thickening agent and emulsifier.

As suitable solvents for the active agent alcohols having 1-6 carbon atoms, and 1-5 hydroxy groups (ethancl, propanol, isopropanol, glycerol, sorbitol, ethylene glycol, propylene glycol; polyalkylene glycols, e g polyethylene glycols (molecular weights of 300 to 10 000); moneglycerides, wherein the fatty acid componant has 12-18 carbon atoms, e g glycerol monolaurate, and other materials in order to improve different properties of the cosmetic preparations. Baotericides, e g hexachlorophen, fungicides and antibiotics, e g neomyeien, can be incorporated as well.

However, the antiperspirant composition can, as evident from above, consist of local anesthetic agent only, whereby then the composition is suitably a mixture of on one hand prilocaine, tetracaine, butanilicaine, and trimecaine in base form and on the other each of the compounds bensocaine, lidocaine, bupivacains, mepivacaine, dibucaine and etidocaine as well as tetracaine, butanilicaine end trimecaine in base form.

These mixtures give oils which can be applied easily or a carrier, which then is applied in the axilla.

Preferred suitable mixtures are prilocaine and bensocaine in the weight ratio 65:35 to 50:20, preferably 70:30; prilocaine and lidocaine in the weight ratio 42:58 to 80:20, suitably 47:53 to 62:38, preferably 55:45;

• prilocaine and etidocaine in the weight ratio 55:45 to 95:5, suitably 50:40 to 80:20, preferably 70:30;
• crilocaine and mepivacaine in the weight ratio 80:20 to 97:3, suitably 85:15 to 90:10, preferably 87:13;
• prilocaine and bupivacaine in the weight ratio of 72:2E to 97:3, suitably 78:22 to 88:12, preferably 85:15.

An antiperspirant composition can be prepared within the following limits for components present.

Above given compounds, except for bensocaine, ketocaine, and 2-(2-n-butyloxyphenoxy)-1-diisopropylaminoethane are represented by the general formulae

wherein R¹ is

and R² is hydrogen or methyl, whereby R² is hydrogen when R¹ is

Bensocaine, 4-aminobenzoic acid ethylester, has the formula

Ketocaine and 2-(2-n-butyloxyphenoxy)-1-diisopropylamino- ethane are represented by the formula

wherein R³ is -COC₃H₇ (Ketocaine) or -OC₄H₉.

• 1-methyl-2-(2,6-xylylcarbamoyl)piperidine is known under the generic name mepivacaine and is sold under the trade mark Carbocaine®
• 1-butyl-2-(2,8-xylylcarbamoyl)piperidine is known under the generic name bupivacaine and is sold under the trade mark Marcaine®
• 2-propylamino-N-(2-tolyl)propionamide is known under the generic name prilocaine and is sold under the trade mark Citanest®

Diethylaminoacet-2,6-xylidide is known under the generic name lidocaine and is sold under the trade mark Cylocaine

2-ethylpropylamino-2,6-n-butyroxylidide is known under the generic name etidocaine and is sold under the trade mark Duranest®

The amount of the compound of the above formula active against perspiration and present in the antiperspirant compositions is usually 0.5-100 % by weight, preferably 0.5-10 %, and more preferably 2-5 %. Higher concentrations than these will usually not be proportionally more active than average or lower consentrotions within the renges gives When lower concentrations than the lower amounts in the ranges given are used the amount of preparation necessary to be applied in order to obtain an amount large enough of the active compound then will become so large that it is unpractical.

The amounts of the compositions given which are applied at one occasion are generally such that 1 to 50 milligrams of active compound, e g lidocaine-prilocaine mixture in base form are deposited, on the place or places, usually in the axillae, to be treated. Preferably 1 to 30 mg, more preferably 5 to 20 mg, are apolied. The use on other parts of the body is usually adopted so that the amount of active compound, which is applied in an amount within above given ranges, is proportional to the surface.

The aqueous, water and alcohol containing or other compositions of the invention in the forms of solutions, emulsions, cremes, ointments, or in any other form are applied onto the skinn normally at ambient temperature, preferably by means of roll-on applicator or with applicator or manual rubbing in. Spraying of a composition may as well be used.

The body place treated is usually the axillae, but also the chest, the bac, the seat, the arms, the palms of the hands the face, the forshead, the genital regions, the thighs and the fest can be treated.

The intention gives sevenal significative advantages and provides for the production of antiperspirant compositions which are superior to the compositions now on the market in several respects. The very small quantities of material needed to be applied are not felt sticky, heavy or desiccating on the skin.

For the determination of the reduction of sweat secretion, several methods can be used. At small quantities a solution containing 5 % prothophtaldialdehyde in xylol is used, which is painted onto the place in question. If sweet persoires in the openings of the sweat-glands these become black--coloured.

When an antiperspirant according to Example 1 is applied in one axilla of a person and placebo (emulsion without local anesthetically active compound) is applied in the second axilla of the same person an definite difference is established between treated and "untreated" axilla using this method. The number of black sweat-gland openings were definitely reduced in the treated axilla of all test persons, whereby treated axillae gave a white impression and un- treatec axillas gave a black impression.

Biological effect

The antiperspiration effect of the present invention was determined in an experimental investigation of dermal analgesia and influence upon adrenaline-induced local sweating by epidermal application of different local anesthetic formulations.

In the investigation it was shown in 12 volunteers that the sweat response, induced by intracutaneous administration of adrenaline, was partly blocked by epidermal application of 1) a combination of prilocaine and lidocaine, 2) lidocaine alone, and 3) prilocaine alone. Both the sweat response and dermal analgesia (tested by pin-pricking) was most pronounced with the formulation consisting of an eutectic mixture of lidocaine base and prilocaine base, in a total concentration of 10 %, as an aqueous emulsion. The other two tested formulations, containing 10 % lidocaine and 10 % prilocaine base respectively, were less effective, both with regard to sweat response inhibition and to dermal analgesia, even if these preduced cemostrable significant effects, over that of a placebo emulsion.

Material and method

12 healthy medical students- took part in the study.

Pre-formed pads, consisting of cellulose fibres, 2 times 2 centimetres, were soaked by a standardized procedure in either an emulsion containing 5 % lidocaine base + 5 % prilocaine base, an emulsifying agent and water, 10 % lidocaine base in the same vehicle, 10 % prilocaine base in the same vehicle, or a placebo emulsion containing the emulsifying agent and water only. On one forearm of the volunteer the four different emulsions were applied under occlusive dressings consisting of an impervious tape, while on the other arm the four emulsions were applied under a non-occlusive dressing, using surgical tape (3M). A certain distance between the application areas was chosen in order to avoid any risk of interference between them.

On the arms of the volunteers 11 and 12 the emulsions were applied directly to the skin, with no cellulose pads, but with occlusive and non-occlusive dressings applied as in the other volunteers.

The apolication time for the pads was 60 minutes.

Immediately after removal of the pads, the square areas under the two types of dressing were marked at the edges. A line was also marked within each applied area dividing them into two identical triangles. One of these surfaces were then used by pin-prick experiments, the other for studying the sweat response.

Testing of dermal analgesia

The pin-pricking procedure was carried out with discosaple dental needles. In each of the test areas 10 pin-pricks were made. 10/10 represents full analgesia, 0/10 no analgesia.

Testing of sweat response

Just under the apax of each test area triangle an intradermal wheal 0.1 ml adrenalin 1:10 000 was injected. Painoninjection was noted. The test area was then swabbed with OPT (5 % ortho- phtaldialdehyde in xylol). After drying the OPT-applied area a plastic ring with adhesive on the back side was placed over the visible vasoconstricted area caused by the adrenaline effect, within the test triangle previously covered by the test compositions. The number of black-coloured sweat pores within the standardized diameter hole in the plastic rings was counted under a direct vision microscope.

Results

Sweat response

The sweat response was most effectively blocked in the lidocaine-prilocaine arees: By the XXX analysis it was found that:

• Lidocaine-prilocaine versus placebo: p=0.001 Occlusive Lidocaine-prilocaine versus lidocaine: p=0.01 bandage Lidocaine-prilocaine versus prilocaine: p=0.05
• Lidocaine-prilocaine versus placebo: p=0.01 Non- occlusiveLidocaine-prilocaine versus lidocaine: p=0.05 bandage Lidocaine-prilocaine versus prilocaine: p=0.05

The lidocaine and priloceine emulsions were also found to be significantly more effective than placebo as evident from Table I below under occlusive bandage and be more effective than placebo under non-occlusive bandage.

• L-P = lidocaine-prilocaine
• L = lidocaine
• P = prilocaine

Statistical data

Results

Dermal analgesia

The lidocaine-prilocaine emulsion was found to be significantly more effective than the lidoceine emulsion, the prilocaine emulsion and the placebo emulsion in preducing dermal analgesia. By the XXX test it was found that:

• Lidocaine-prilocaine versus placebo: p=0.001 Under occlu-Lidocaine-prilocaine versus lidocaine: p=0.001 sive bandage Lidocaine-prilocaine versus prilocaine: p=0.01
• Lidocaine-prilocaine versus placebo: p=0,01 Under non-Lidocaine-prilocaine versus lidocaine: p=0.01 -occlusive Lidocaine-prilocaine versus prilocaine: p=0.01 bandage

The lidocaine and prilocaine emulsions were found to be insignificantly more effective than the placebo emulsion under occlusion as well as under a non-occlusive bandage. CF Table II below.

Statistical data

All volunteers reported pain at the intradermal injection of adrenaline solution at the placebo, the lidocaine and the prilocaine areas but not at the lidocaine-prilocaine areas.

Conclusion

As evident from the results given above the antiperspirant effect is more pronounced than the analgesic effect is. This is of no disadvantage but rather the contrary, as an analgesia is not wanted using an antinerspirant day-in day-out.

The following, non-restristing Exemple shows a preferred embodiment of the invention. If nothing alse is given parts are parts per weight and degrees are given in degrees Celsius.

Example 1

An antiperspirant in the form of an emulsion was prepared according to the following

The local anesthetic bases are added to Arlaton® and a part of the water whereupon Carbopol® dissolved in the remaining water is added. The mixture is stirred until the emulsion is ready.

A specific advantage using the compositions according to the present invention where the active component is a local anesthetical substance of amide type is the documented low frequency of allergic complications contrary to other generally used agents.

The present compositions can also contain other active ingredients. A further aspect and preferred embodiment cf the invention is thus characterized in that the antiperspirant composition of the invention further contains a compound which has an effect against sweat secretion, as e g an anticholinergicum or an antiadrenergicum or an agent which inhibits transportation of body liquids in the peripheral vessels.

It is also possible to introduce aluminum compounds commonly used in order to obtain combination effects.