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  Pharmaceutical Patents  

 

Title:  Benzoyl peroxide compositions having increased potency
United States Patent:
7,326,420
Issued: 
February 5, 2008

Inventors: 
Burkhart; Craig G. (Toledo, OH), Burkhart; Craig N. (Toledo, OH)
Appl. No.: 
10/917,240
Filed: 
August 12, 2004


 

Woodbury College's Master of Science in Law


Abstract

A benzoyl peroxide composition having increased potency includes benzoyl peroxide, a tertiary amine and/or a transition metal, and a base that increases radicals formed by the peroxide.

Description of the Invention

BACKGROUND OF THE INVENTION

This invention relates in general to methods of treating skin conditions such as acne, and in particular to methods of increasing the efficacy of peroxides such as benzoyl peroxide in the treatment of skin conditions.

The pathophysiology of acne vulgaris, the most common cutaneous disease, is the consequence of the interplay of follicular hyperkeratinization, bacteria in the follicular canal, and sebum production. The exact mechanism triggering the development of the comedone and the stimuli causing the non-inflamed lesion to become provoked are poorly understood. The microbiology of acne vulgaris and its immunologic ramifications constitute a major thrust of present research in the elucidation of the pathogenesis of inflammatory acne. Within the microbial flora of the pilosebaceous unit, P. acnes is the most meaningful organism in acne causation.

The methods of acne therapy are usually grouped into several categories such as keratolytics, antibacterials, sebosuppressives, and hormones. Benzoyl peroxide (BP) is the most widely used topical agent for acne since its introduction in the 1960's. BP is very effective for the treatment of acne because it is antibacterial, functions as a peeling agent, has comedolytic activity, and reduces free fatty acid levels. Concomitant topical treatment of BP and erythromycin is stated to be superior to BP alone. However, no synergistic activity has been found with this combination. Instead, such combination therapies are hypothesized to gain their efficacy by the coupled action of two effective treatments.

SUMMARY OF THE INVENTION

This invention relates to methods of increasing the efficacy of peroxides such as benzoyl peroxide in the treatment of skin conditions such as acne. In a preferred embodiment, the invention relates to methods of increasing radicals formed by peroxides on/in the skin, more specifically near/in the comedone, for topical use in dermatology.

In a specific embodiment, the invention relates to the use of transitional metals such as Cu(1) and ferrous ions to increase the efficacy of peroxides such as benzoyl peroxide.

In another embodiment, the invention relates to a method by which a peroxide such as benzoyl peroxide and its activator (or adjunctive agent) are added to the skin surface at the same time (and not days or months before). This ensures that the ingredients are not inactivated or lost strength by being placed together prior to usage.

In another embodiment, the invention relates to the use of a more soluble form of peroxide such as benzoyl peroxide to increase its efficacy.

In another embodiment, the invention relates to the addition of a side chain to a peroxide such as benzoyl peroxide so that it is activated by light.

In a further embodiment, the invention relates to the addition of a tertiary amine to a peroxide such as benzoyl peroxide at the time of skin application, to improve the efficacy of the peroxide. This could include any tertiary amine structure except for an erythromycin structure.

In another embodiment, the invention relates to the addition of dapsone or other material to a peroxide such as benzoyl peroxide to improve its efficacy.

Various advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention relates to methods of increasing the efficacy of peroxides such as benzoyl peroxide in the treatment of skin conditions such as acne. In a preferred embodiment, the invention relates to methods of increasing radicals formed by peroxides on/in the skin, more specifically near/in the comedone (but not limited thereto), for topical use in dermatology. The methods use the radicals formed by peroxides such as benzoyl peroxide, optimizing conditions such that the skin/comedone is the only place they are formed as opposed to in a storage container or wherever the benzoyl peroxide happens to be from the time of application to when the benzoyl peroxide breaks down into its radicals or is metabolized).

The methods of the invention may use the principles of photodynamic therapy directed at acne. Instead of forming radicals in cancer cells, the methods form radicals in/by the comedone (skin surface, sebum within P. acnes). Location and timing of formation of radicals is a very important part of the methods.

The methods use the assumption that radicals derived from BP or other peroxides are the most useful in acne therapy (as opposed to reactive oxygen intermediates used in photodynamic therapy).

In a specific embodiment, the invention relates to the use of transitional metals such as Cu(1) and ferrous ions to increase the efficacy of peroxides such as benzoyl peroxide. The use of transitional metals such as Cu(1) and ferrous ions (as alluded to in the text) to increase the efficacy of benzoyl peroxide. It is anticipated that such an addition to benzoyl peroxide would increase the generation of benzoyloxyl radicals.

The transitional metals include all the elements between Group IIA and IIIa in the periodic table. The list includes zinc, cadmium, mercury, scandium, titanium, vanadium, chromium, manganese, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, lanthanum, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, mercury, actinium, unnilquadium, unnilpentium, unnilhexium, and uniseptium.

A few characteristics of transitional metals include: most are harder and more brittle with higher melting points, boiling points, and heats of vaporization than the non-transitional metals. their ions and compounds are usually colored. they form many complex ions. most exhibit multiple oxidation states. many of them are paramagnetic, as are many of their compounds. many of the metals and associated compounds are effective catalysts.

In another embodiment, the invention relates to a method by which a peroxide such as benzoyl peroxide and its activator (or adjunctive agent) are added to the skin surface at the same time (and not days or months before). An example of such would be a better package system in which the various ingredients that would be added to benzoyl peroxide would be put into a dispenser with two or three chamber (depending upon the number of items combined) to separate the product's ingredients so they do not interact until the instant you apply them to one's acne. This separation would ensure that the ingredients are not inactivated or lost strength by being placed together prior to usage.

Another example of such a system would be benzoyl peroxide (bp) dissolved in a hydrophobic solvent and the activator in a polar solvent. The BP and activator wouldn't meet until applied onto the skin surface. Lipophilic carriers are well known in the art. For an example of the activator in a hydrophilic solvent, both protic and aprotic solvents are included. Protic solvents such as methanol, ethanol, formamide, N-methylformamide, and water, a hydrogen is attached to the electronegative part of the reagent. The hydrogen has a proton-like character and strongly reacts with anionic nucleophiles. Aprotic solvents do not contain positively polarized hydrogens. These include acetone, acetonnitrile, N,N-dimethylformamide, DMSO, hexamaethylphophoric triamide--the aprotic solvents increase the reactivity of nucleophiles in SN2 reactions (the possible mechanism of radical formation by the BP tertiary amine combination).

Retin A micro is an example of a product released by a polymer. The retin A is stored in a small polymer bead. After application of these beads onto the skin, retin A slowly diffuses out of the polymer and into the skin. The invention would have the activator of benzoyl peroxide radical formation contained in a similar polymer. The activator would be slowly released (by diffusion or breakdown of the polymer) into the skin allowing it to react with BP. Alternatively, the BP could be stored in and released from the polymer. Or, both the activator and BP could be released from their own individual polymers to react when the meet (in the environment of the skin/comedone).

In another embodiment, the invention relates to the use of a more soluble form of peroxide such as benzoyl peroxide to increase its efficacy. The use of a more soluble form of benzoyl peroxide. The present-day products actually use benzoyl peroxide in the form of crystals. We are able to solubilize benzoyl peroxide either by altering its hydric solvents, or by adding a side chain to its structure.

In another embodiment, the invention relates to the addition of a side chain to a peroxide such as benzoyl peroxide so that it is activated by light. We could also add a side chain to benzoyl peroxide so that it is activated by light.

In a further embodiment, the invention relates to the addition of a tertiary amine to a peroxide such as benzoyl peroxide at the time of skin application, to improve the efficacy of the peroxide. This could include any tertiary amine structure except for an erythromycin structure. We believe that benzoyl peroxide efficacy can be improved by adding a tertiary amine at the time of skin application. Therefore, we would be including all substances (and chemicals) which have a tertiary amine within the provisional patent, be they antibiotics or whatever. The invention would include all tertiary amine structures, save for the erythromycin structure that is presently used in a commercial product named benzymycin.

Some nonlimiting examples of tertiary amines include Alfuzosin, Alimemazine, Analgesic drug (Reference 97), Atropine, alpha,alpha-bis [3-(N-benzyl-N-methyl-carbamoyl)-piperidino]-p-xylene dihydrobromide, Bupivacaine, cis-trans-Cavinton, Cloperastine, Cyamemeazine, Cyclopentolate, 2-(4,5-dihydro-1H-imidazol-2-yl)-2-propyl-1,2,3,4-tetrahydropyrrolo]3,2,1- -hi[-indole, 1-decyl-3-(N,N-diethylcarbamoyl) piperidine hydrobromide, Diltiazem, Dimethindene, Diperodone, Disopyramide, Disopyamide, semipreparative, Dixyrazine, Doxazosin, Dropropizine, Hydroxychloroquine and metabolites, Ketoconazole, Laudanosine, Marcaine, Medetomidine, Mepivacaine, Mepivacaine (micro column), Meptazinol, Methadon, Nefopam, Nicotine, Omeprazole, Oxybutynin, Oxyphencyclimide, Pheniramine, 3-PPP, Procyclidine, Promethazine, Proxyphylline, Remoxipride, Tetrahydrozoline, Tetramisole, Tetramisole (micro column), Thioridazine ring-sulphoxide, Tolperisone, Trihexyphenidyl, Trimipramine, Tropicamide, Vamicamide, Verapamil, and Vinca alcaloids. The structures and other characteristics of these tertiary amines can be found on the internet at www.chromtech.se/tertiary.htm. The listed amines are all drugs, but the methods of the invention are not limited to just drugs--any tertiary amine would work.

Along with transition metals, tertiary amines potentiate radical formation by BP. A possible mechanism involves reaction of the amine and BP by a S.sub.N2 mechanism. The intermediate thus formed thermally decomposes to benzoyloxy radicals and an amine radical cation. The benzoyloxy radicals may further decompose into phenyl radicals. All of these radicals can react with biological molecules possibly causing some biological effect.

In another embodiment, the invention relates to the addition of dapsone to a peroxide such as benzoyl peroxide to improve its efficacy. Heme is a protoporphyrin. P. acnes actually produces protoporphyrins. 5-aminolevulinic acid (ALA) increases protoporphyrin production by P. acnes. ALA is the same stuff used in photodynamic chemotherapy and photodynamic antimicrobial chemotherapy. Methylene blue, toluidine blue O, phthalocyanine, and haematoporphyrin derivative could also be used. Phenothiazinium dyes could also be used. These materials might work by depleting the antioxidant levels in/around the comedone allowing the BP derived radicals to reach the comedone or spread further throughout the comedone.

Viagra (sildenafil) increases NO production by blood vessels (and maybe the skin). It is an example of a molecule inducing the skin to produce a benzoyl peroxide activator.
 

Claim 1 of 20 Claims

1. A method of treating a bodily condition comprising topically applying to the body of a human or animal a combination of a peroxide and a tertiary amine, the tertiary amine increasing radicals formed by the peroxide on the body to thereby increase the efficacy of the peroxide in the treatment of the condition, and increasing the potency of the peroxide by at least one of the following steps: (a) combining the peroxide with a material that further increases radicals formed by the peroxide; (b) mixing the peroxide and the tertiary amine after they have been applied to the body; (c) energizing reaction of the peroxide with the tertiary amine on the body; (d) treating the body with an oral or topical anti-oxidant; (e) increasing penetration of the peroxide through a surface of the body; and (f) heating at least one of the peroxide and the tertiary amine before applying them to the body.

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If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.

 

 

     
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