ENHANCED ACNE TREATMENT COMPOSITION

Abstract

The present invention relates to a composition for topical application to human skin comprising by weight: about 0.01% to about 35% salicylic acid, about 0.01% to about 65% solubilizing, agent selected from one or more alkali and alkaline earth hydroxides, alkali and alkaline earth metal salts of organic acids, wherein the solubilizing agent is present in an amount sufficient to solubilize the salicylic acid in the absence of alcohol, a cosmetically acceptable aqueous medium in which the salicylic acid and solubilizing agent are dissolved.

Claims

1. A composition for topical application to human skin comprising by weight: about 0.01% to about 35% salicylic acid, about 0.01% to about 65% solubilizing agent selected from one or more alkali and alkaline earth hydroxides, alkali and alkaline earth metal salts of organic acids, a cosmetically acceptable aqueous medium in which the salicylic acid and solubilizing agent are dissolved, wherein said solubilizing agent is present in an amount sufficient to solubilize the salicylic acid in the absence of alcohol.

2. The composition of claim 1 wherein the salicylic acid is present in an amount from about 0.5% to about 33% by weight.

3. The composition of claim 1 wherein the cosmetically acceptable aqueous medium comprises at least one surfactant.

4. The composition of claim 3 wherein said at least one surfactant is selected from one or more of PPG-5-ceteth-20, ammonium xylene sulfonate and ammonium lauryl sulfate.

5. The composition of claim 1, wherein the cosmetically acceptable medium contains salts of citric acid.

6. The composition of claim 1, wherein the cosmetically acceptable medium contains a chelating agent.

7. The composition of claim 1 in combination with a non-woven pad as a dispensing medium.

8. The composition of claim 7 wherein said pad is saturated with said composition, and is situated within a container for storage prior to use.

9. The composition of claim 1 which is alcohol free.

10. The composition of claim 1 which is prepared at ambient temperature.

11. The composition of claim 9 which is prepared at ambient temperature.

12. A method for preparing a composition for topical application to human skin comprising, one or more alkali or alkaline earth metal hydroxides and/or organic acid salts with sufficient water for dissolution, adding a desired amount of salicylic acid and mixing at ambient temperature until dissolved, and/or optionally adding a solubilizing agent composition and mix at room temperature to dissolve.

13. The method of claim 12 where the solubilizing agent mixture comprises one or more of a surfactant, antifoaming agent, chelating agent, olfactory agent and or a preservative.

14. The method of claim 13 wherein the salicylic acid is present in an amount from about 0.01% by weight to about 35% by weight.

15. The method of claim 14 wherein the salicylic acid is present in amount of from about 0.5% by weight to about 2% by weight.

16. A method of treatment of a human with a skin condition comprising applying the composition of claim 1 to skin of the human, wherein the salicylic acid is present in the composition in an amount effect to reduce a symptom of the skin condition.

17. The composition of claim 1, wherein the solubilizing agent is present in the composition in an amount sufficient to solubilize the salicylic acid when the salicylic acid is mixed with a solution comprising the solubilizing agent and water at a room temperature in the range of about 18-24° C.

18. The composition of claim 1, wherein the solubilizing agent comprises an alkali or alkaline earth metal hydroxide.

19. The composition of claim 1, wherein the solubilizing agent comprises an alkali or alkaline earth metal salt of an organic acid, and wherein the organic acid is selected from the group consisting of citric acid, glycolic acid, lactic acid, Tartaric acid, and malic acid.

20. The method of claim 10, wherein the composition is prepared at a room temperature in the range of 18-24° C. without heating.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0009] The salicylic acid which is the active ingredient of the composition of the invention must be adequately solubilized in the absence of the alcohol. The term “alcohol” as used herein refers to the lower alkanols, in particular, methanol, ethanol, propanol and isopropanol.

[0010] Salicylic acid occurs in the form of acicular crystals or crystalline powder with a melting point of 157-159° C. and a strong tendency to discolor in sunlight and in the presence of ferric salts. While salicylic acid is only slightly soluble in water, salicylic acid is known to be solubilized by mixing with various diluents, including alcohol, sodium tetraborate (borax), sodium carbonate or sodium bicarbonate. The reaction with these solubilizing agents both eliminates the crystalline nature of the salicylic acid and buffers the resulting solution to any degree desired, so that a product may be prepared which is close to skin pH. Sodium tetraborate has been preferred in some conventional preparations.

[0011] Additionally, in conventional applications preferably, salicylic acid and a solubilizing agent are heated to about 45-50° C. in an aqueous mixture until a clear solution is obtained, with best results achieved by heating with strong agitation. The resulting solutions do not recrystallize, even when subjected to several freeze-thaw cycles (−20 to +45° C.), and no color change occurs during such cycles.

[0012] The instant invention provides a surprising and viably economic formulas with ease of preparation with such desirable physical attributes as above mentioned of an acne treatment composition comprising salicylic acid solubilized in a variety of agents, which can be inorganic and organic bases, such as alkali and alkaline earth hydroxides, e.g., sodium hydroxide and potassium hydroxide, and alkali and alkaline earth metal salts of organic acids, such as monosodium citrate, or trisodium citrate, disodium citrate, and dissolved in a cosmetically acceptable aqueous medium to yield desired pH, and prepared at ambient temperature requiring no external heat application. The compositions are easily prepared in batchwise manner for introduction into drug application products.

[0013] The term “cosmetically acceptable aqueous medium” as used herein means that of human epidermis compatible drug carrier, and which is as generally known. A drug carrier is any substrate used in the process of drug delivery which serves to improve the selectivity, compliance, effectiveness, and/or safety of drug administration. Drug carriers are primarily used to control the release of a drug into systemic circulation. This can be accomplished either by slow release of the drug over a long period of time (typically diffusion) or by triggered release at the drug's target by some stimulus, such as changes in pH, application of heat, and activation by light. Drug carriers are also used to improve the pharmacokinetic properties, specifically the bioavailability, of many drugs with poor water solubility and/or membrane permeability.

[0014] A wide variety of drug carrier systems have been developed and studied, each of which has unique advantages and disadvantages. Some of the more popular types of drug carriers include liposomes, polymeric micelles, microspheres, and nanoparticles. Different methods of attaching the drug to the carrier have been implemented, including adsorption, integration into the bulk structure, encapsulation, and covalent bonding. Different types of drug carrier utilize different methods of attachment, and some carriers can even implement a variety of attachment methods. Any of such known methods, or as yet unknown, are contemplated for use herein.

[0015] The composition of the invention can contain about 0.01% to about 35% by weight salicylic acid, preferably from about 0.5 to about 20% by weight, and more preferably about 0.5 to about 5% by weight. For solubilization agent, from about 0.01% to about 65% by weight of one or more solubilizing agents will preferably be used. In order to operate within FDA guidelines for over-the-counter medications, the compositions preferably contain in some formulations from about 0.5 to 2.0% by weight salicylic acid.

[0016] Solubilizing agents contemplated herein are preferably selected from alkali or alkaline earth metal hydroxides and/or organic acid salts, or a mixture thereof of two or more of said solubilizing agents, in an amount(s) sufficient to fully or desirably solubilize the salicylic acid (in an absence of alcohol) in a cosmetically aqueous medium in which the salicylic acid and solubilizing agent(s) are dissolved.

[0017] In preferred embodiments, the composition of the invention may be formulated, by way of example, into a clear solution, a gel, a cream or a water-in-oil emulsion. When the salicylic acid is to be formulated into a clear solution as described above for direct application or application with a pad, the salicylic acid and solubilizing agent will be present in a cosmetically acceptable medium, generally containing one or more solubility enhancing agents, such as, but not limited to, surfactants and hydrotropes, for example, PPG-5-ceteth-20, ammonium xylene sulfonate or ammonium lauryl sulfate, among others. Ammonium xylene sulfonate and ammonium lauryl sulfate are preferred, and are preferably used in combination. Some non-limiting examples of other commonly used surfactants and emulsifying agents for preparation of gels and creams, include sodium lauryl sulfate, ammonium laureth sulfate, disodium lauryl sulfosuccinate, cocoamphocarboxyglycinate, decyl polyglucoside, cetearyl alcohol, stearyl alcohol, cocamidopropyl betaine, decyl glucoside, glyceryl cocoate, sodium cocoyl isethionate, almond glycerides, sodium lauryl sulphoacetate, sodium lauroyl sarcosinate, sodium methyl cocoyl taurate, sucrose cocoate, polysorbate 20, polysorbate 80, xanthan gum, cellulose, Polyglyeeryl-3 Triolivate, Sorbitan Isostoarate Octyidociecyl Oleate, Glycereth-18 Polyhydroxystearate, Cetyl PEG/PPG-10/1 Dimethicone and Hydroxyethyl Acrylate/Sodium Acryloydimethyl Tauate Copolymer. Other components of the medium may include natural plant botanical extracts, preservatives and fragrances, citric acid and a chelating agent such as tetrasodium EDTA.

[0018] As mentioned, the invention also contemplates the use of one or more preservatives commonly employed in cosmetics, and which are known to preserve a formulation, ensure the durability of cosmetic products, and in formulations containing water are efficacious in arresting microorganisms' development during formulation, shipment, storage or consumer use. Preferred for use herein are broad-spectrum preservatives effective at very low concentrations, for example, about 0.001 wt/wt % to about 1.000 wt/wt % of a formula, and which can include, without limitation: [0019] Aldehydes, such as formaldehyde, DMDM hydantoin, imadozolidinyl urea, diazolidinyl urea: safeguard against bacteria and some fungi [0020] Glycol ethers, such as phenoxyethanol and caprylyl glycol: safeguard against some bacteria [0021] Isothiazolinones, such as methylisothiazolinone: safeguard against bacteria and fungi [0022] Organic acids, such as benzoic acid, sorbic acid, levulinic acid, anisic acid: safeguard against fungi and some bacteria [0023] Additional preservatives such as thymol, O-cymen-5-ol and phenylpropanol; antibacterial and antifungal activity as well as preservative boosting ability
Parabens, such as methylparaben, ethylparaben, propylparaben, are also commonly used as preservatives in cosmetics although there is currently a concern as to whether they may have an effect on human health. Accordingly, glycol ethers, such as phenoxyethanol, are preferred insofar as they are considered a milder alternative to traditional preservatives and a paraben replacer. Such glycol ethers may be combined with, for example, caprylyl glycol, sorbic acid, potassium sorbate, benzoic acid, or EDTA to enhance broad spectrum efficacy. Various antioxidants are also contemplated, such as, without limitation, vitamin E, vitamin C derivaitives, and grapefruit seed extract. While preferred ranges of concentration are recited, any effective amount that is safe for human health is also contemplated for use in the invention.

[0024] Multi-active compounds are also contemplated for use herein, such as ethylhexylglycerin, a type of alkyl glyceryl ether, which is used for its surfactant, emollient, skin-conditioning and antimicrobial properties, and preferred for use in amounts of from about 0.001% wt/wt to about 1.000% wt/wt, although any effective amount is contemplated for use.

[0025] Preferred fragrances for use herein include without limitation, an olfactory agent in amounts of from about 0.001% wt/wt to about 10.000% wt/wt and/or menthol used in many personal care products as both fragrance and for its analgesic properties, and preferred from use in amounts of from about 0.001 wt/wt % to about 1.000 wt/wt %, and, again, such are contemplated for use herein in any effective amount.

[0026] Further contemplated for use herein is simethicone (antifoaming agent), known for use in lubrication and antifoaming application of topical preparations, anti-whitening properties in acne and other dermatological ointments, creams and lotions, and preferred for use in amounts of from about 0.001% wt/wt to about 1.000% wt/wt, although any effective amount is contemplated for use.

[0027] In the embodiment of the invention wherein the composition is formulated as a clear solution, the composition may be applied directly to the affected area, or may be applied with a non-woven pad as is well known in the art. In particular, the composition may be dispensed from a container containing one or more non-woven pads which are saturated with the solution.

[0028] In the embodiments wherein the composition is formulated as a cream or gel, the composition may be applied directly to the affected area with a designed spot applicator such as, but not limited to, a roll on applicator, a thin brush applicator, a hand held sponge applicator or the like.

[0029] The following non-limiting examples are presented to better illustrate some preferred embodiments. It is to be understood that the disclosed embodiments described herein are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific details disclosed herein are not intended to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to variously employ the invention in virtually any appropriately detailed composition as limited by one's own imagination. Various modifications and changes are contemplated without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

EXAMPLES

Example 1

[0030] A clear solution is prepared with the following composition:

TABLE-US-00001 Active Ingredients Component % by weight salicylic acid 0.001-33.000 Inactive Ingredients Component % by weight Purified Water q.s. to 100% Ammonium Lauryl Sulfate 0.001-5.000 Ammonium Xylenesulfonate 0.001-7.000 Tetrasodium EDTA 0.001-1.000 Preservative 0.001-1.000 Antifoaming agent 0.001-1.000 Olfactory Agent 0.001-10.000 Menthol 0.001-1.000 Ethylhexylglycerin 0.001-1.000 Botanical extracts 0.001-25.000 Sodium citrate 0.001-15.000 Sodium Hydroxide 0.001-15.000 Final formula concentration must add to 100%

Example 2

[0031] A clear solution is prepared with the following composition:

TABLE-US-00002 Active Ingredients Component % by weight salicylic acid 31.000 Inactive Ingredients Component % by weight Purified Water 48.82500 Ammonium Lauryl Sulfate  3.2000 Ammonium Xylenesulfonate  6.0000 Tetrasodium EDTA  0.0100 Preservative  0.5000 Antifoaming agent  0.0100 Olfactory agent  0.0250 Menthol  0.0500 Ethylhexylglycerin 0.001-1.000 Botanical extracts  0.1000 Sodium citrate  2.1400 Sodium Hydroxide  8.1400 Final formula concentration must add to 100%

Example 3

[0032] A gel is prepared with the following composition:

TABLE-US-00003 Active Ingredients Component % by weight salicylic acid 0.001-10.000 Inactive Ingredients Component % by weight Purified Water q.s. to 100% Ammonium Lauryl Sulfate 0.001-5.000 Ammonium Xylenesulfonate 0.001-7.000 Tetrasodium EDTA 0.001-1.000 Preservative 0.001-1.000 Antifoaming agent 0.001-1.000 Olfactory Agent 0.001-10.000 Menthol 0.001-1.000 Glycerin 0.010-10.000 Xanthan Gum 0.010-1.5000 Ethylhexylglycerin 0.001-1.000 Botanical extracts 0.001-25.000 Sodium citrate 0.001-15.000 Sodium Hydroxide 0.001-15.000 Final formula concentration must add to 100%

Example 4

[0033] A cream is prepared with the following composition:

TABLE-US-00004 Active Ingredients Component % by weight salicylic acid 0.001-10.000 Inactive Ingredients Component % by weight Purified Water q.s. to 100% Ammonium Lauryl Sulfate 0.001-5.000 Ammonium Xylenesulfonate 0.001-7.000 Tetrasodium EDTA 0.001-1.000 Preservative 0.001-1.000 Antifoaming agent 0.001-1.000 Olfactory Agent 0.001-10.000 Menthol 0.001-1.000 Glycerin 0.010-10.000 Xanthan Gum 0.010-1.5000 Polyglyceryl-3 Triolivate, Sorbitan Isostearate, 0.010-10.000 Octyldodecyl Oleate Ethylhexylglycerin 0.001-1.000 Botanical extracts 0.001-25.000 Sodium citrate 0.001-15.000 Sodium Hydroxide 0.001-15.000 Final formula concentration must add to 100%

[0034] Procedures for aqueous solutions, cream and gel (Ambient temperature): [0035] 1. In main vessel, water and alkaline metals salts are added and mixed until solids are dissolved. [0036] 2. Salicylic acid is next added to main vessel. Mixing is performed at room temperature and until completely dissolved. [0037] 3. Mix Xanthan gum with glycerin and water, add to main tank when fully hydrated. Xanthan gum is a representative of a preferred structuring agent for use in the invention. One of skill in the art will appreciate that other structuring agents may be used when the formulation calls for a structuring agent. [0038] 4. In a separate vessel prepare premix: add the detergents/surfactants, antifoaming agent, chelating agent, flavors, and preservatives. Mix at room temperature. For the cream or gel formulations, mix into the organic phase any desired or required emulsifiers. [0039] 4. Transfer premix to main vessel. Rinse side vessel with small amount of water, add the rinse to main vessel and mix as desired. [0040] 5. Conduct testing on the finish formula before packaging. [0041] 6. Package the formula.

Example 5

[0042] A water in oil emulsion is prepared with the following composition:

TABLE-US-00005 Active Ingredients Component % by weight salicylic acid 0.001-20.000 Inactive Ingredients Component % by weight Purified Water q.s. to 100% Phase A Squalane 0.001-20.000 Dimethicone 0.001-20.000 Cetyl PEG/PPG-10/1 Dimethicone 0.010-5.000 Olfactory Agent 0.001-10.000 Fumed Silica 0.001-5.000 Phase BTetrasodium EDTA 0.001-1.000 Preservative 0.001-1.000 Zinc Chloride 0.001-1.000 Menthol 0.001-1.000 Glycerin 0.010-10.000 Ethylhexylglycerin 0.001-1.000 Sodium citrate 0.001-15.000 Sodium chloride 0.001-1.000. Sodium Hydroxide 0.001-15.000 Final formula concentration must add to 100%

[0043] Procedure for Alcohol Free; Water in Oil Emulsion (Ambient Temperature)

TABLE-US-00006 1 Disperse the emulsifier into the oils & fragrance in phase A with mixing 2 Disperse the silica into Phase A 3 Prepare Phase B separately, adjust pH to 3.5-5, if necessary, using sodium citrate or sodium hydroxide 4 Add Phase B very slowly into Phase A while stirring intensively. 5 Homogenize to finish the emulsification. 6 Fill into an appropriate container (tube, jar, pen applicator etc.)

[0044] While the invention has been described with particular reference to some preferred embodiments in the interest of complete definiteness, it is to be understood that it may be embodied in a variety of forms diverse from these specifically shown and described without departing from the spirit and scope of the invention and defined by the appended claims.