Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Nitrogen containing other than solely as a nitrogen in an...
Reexamination Certificate
2001-12-13
2002-12-17
Criares, Theodore J. (Department: 1617)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Nitrogen containing other than solely as a nitrogen in an...
C424S401000, C424S602000, C424S682000
Reexamination Certificate
active
06495602
ABSTRACT:
FIELD OF INVENTION
The present invention relates to a novel astringent and keratolytic (urea containing) topical pharmaceutical base composition to which other drugs can be added, for example, an anti-pruritic drug like lidocaine, a corticosteroid like hydrocortisone or a combination thereof.
BACKGROUND OF THE INVENTION
Urea has been long recognized as a cosmetic ingredient in formulations acting as a humectant and moisturizer. There have been reports of keratolytic activity attributed to urea with the ability at high concentrations to solubilize and denature protein. High concentrations of urea are also known to have a mild, antimicrobial effect.
Astringents are locally applied compounds which precipitate proteins and shrink mucous membranes. Typically used are aluminum sulfate and calcium acetate. Astringents add significant value to topical cream products and in the healing of damaged skin.
The pH of normal skin is about 4.5-5.5. This acidic pH of the skin provides a natural protection and is referred to as the “Acid Mantle” of the skin. Microorganisms prefer a pH in the range 6-7 to thrive and are therefore held in check by the acidic pH of the skin.
There is a need in the industry for improving on compositions for treating inflamed and pruritic conditions more effectively. A need also exists for a topical pharmaceutical base into which other drugs can be incorporated to provide better efficacy and improved healing of the dermal condition.
SUMMARY OF THE INVENTION
The present invention concerns the finding that the use of topical keratolytics, such as urea, improve drug penetration and the efficacy of traditional anesthetic agents, such as, for example, lidocaine and corticosteroid action.
Accordingly, as one embodiment, the present invention includes a novel topical pharmaceutical base containing astringents and urea which base can be used to incorporate drugs, such as anesthetics and corticosteroids or a mixture thereof. The topical base includes about 1 to about 40 wt % urea; about 0.01 to about 1 wt % of an astringent, and dermatologically acceptable excipients.
The present invention includes as a second embodiment a dermatological composition for treating pruritus conditions containing about 1 to about 40 wt % urea; about 0.01 to about 1 wt % of an astringent; about 0.01 to about 10 wt % of an anesthetic agent, and dermatologically acceptable excipients.
In a third embodiment, the present invention includes a dermatological composition for treating pruritic and inflamed conditions containing about 1 to about 40 wt % urea; about 0.01 to about 1 wt % of an astringent; about 0.01 to about 10 wt % of an anesthetic agent; about 0.001 to about 10 wt % of a corticosteroid, and dermatologically acceptable excipients.
The above dermatological compositions may preferably include one or more non-ionic surfactants. The compositions are preferably creams and have a pH between about 3.0 and 6.5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention first includes a novel pharmaceutical base which drugs can be incorporated into such as anesthetics and corticosteroids or mixtures thereof.
The pharmaceutical base contains urea and an astringent. The urea is contained in an amount from about 1 to about 40 wt % of the total composition. Preferably compositions contain from about 5 to about 35 wt % . The astringent ranges from about 0.01 to about 1 wt % of the composition. Combining astringents and urea in a pharmaceutically acceptable topical base at an acidic pH provides a unique combination of factors for applying topical drugs to the skin and for skin healing.
Astringents precipitate proteins and shrink mucous membrane. Commonly used astringents include salts of cations, including aluminum, zinc, manganese, iron and bismuth; other salts that contain the afore-mentioned metals, such as permanganates; and tannins and related polyphenolic compounds. Examples of specific astringents include aluminum chlorohydrates including hydrate of aluminum chloride hydroxide, aluminum chloride, aluminum sulfate, calcium acetate, zinc sulfate, aluminum ammonium sulfate, aluminum potassium sulfate, aluminum acetate, calamine (iron oxide mixed with zinc oxide), zinc sulfate, zinc caprylate, zinc chloride, zinc oxide, and tannic acid. Preferred astringents include aluminum sulfate, calcium acetate or a mixture thereof.
Examples of drugs incorporated in this topical base include the compositions of the present invention which include about 0.001 to about 10 percent by weight of a corticosteroid, e.g. hydrocortisone or hydrocortisone acetate, or about 0.01 to about 10 percent by weight of an anesthetic agent, e.g. lidocaine or a pharmaceutically acceptable salt thereof. In one embodiment, the weight ratio of anesthetic to corticosteroid is between about 6:1 to about 3:1.
Local anesthetics include, for example, benzocaine, bupivacaine, cocaine, etidocaine, lidocaine, mepivacaine, paroximine, prilocaine, procaine, proparacaine, ropivicaine, and tetracaine.
Corticosteroids include, for example, alclometasone dipropionate, amcinonide, augmented betamethasone dipropionate, beclomethasone dipropionate, betamethasone, betamethasone benzoate, betamethasone dipropionate, betamethasone sodium phosphate, betamethasone valerate, clobetasol propionate, clocortolone pivalate, cortisone, desonide, desoximetasone, dexamethasone, dexamethasone acetate, dexamethasone sodium phosphate, diflorasone acetonide, diflorasone diacetate, fluocinolone acetonide, flucinonide, flunisolide, fluocinolone acetonide, flurandrenolide, fluticasone propionate, halcinonide, halobetasol propionate, hydrocortisone, hydrocortisone acetate, hydrocortisone butyrate, hydrocortisone sodium phosphate, hydrocortisone valerate, methylprednisolone, methylprednisolone acetate, methylprednisolone sodium succinate, mometasone furoate, prednisolone acetate, prednisolone sodium phosphate, prednisolone tebutate, prednisone, triamcinolone, triamcinolone acetonide, triamcinolone diacetate, and triamcinolone hexacetonide. Topical corticosteroids are typically applied as creams, ointments or gels.
Glucocorticoids that are commonly applied topically include betamethasone dipropionate, clobetasol propionate, diflorasone diacetate, halobetasol propionate, amcinodide, flucinonide, halcinonide, betamethasone valerate, diflorasone diacetate, triamcinolone acetonide, flurandrenolide, hydrocortisone valerate, mometasone furoate, hydrocortisone butyrate, aclometasone dipropionate, flucinonolone acetonide, and dexamethasone sodium phosphate.
Preferably, the compositions of the present invention include about 0.01 to about 2.0 percent by weight hydrocortisone and about 1.0 to about 5.0 percent by weight lidocaine and 15 percent urea. In the compositions of the present invention, the ratio of lidocaine to hydrocortisone ranges from about 1.0 to 00.01 to about 5.0 to 2.5. A particularly preferred composition comprises about 3.0 percent by weight lidocaine and about 0.5 percent by weight hydrocortisone with 10 percent urea.
Further, the vehicle used to deliver topical drug products can play an important role in the efficacy and stability of product. This is of particular importance in the development of these formulations.
Generally topical cream formulations are oil in water emulsions (o/w) which allow easy application of the product on the skin without leaving an oily residue. Most o/w cream formulations use anionic surfactants (e.g. sodium lauryl sulfate) in their emulsion system to provide a physically and chemically stable product. Long term stability is an important consideration in the commercialization of a product. Attempts to make formulations with anionic surfactants and lidocaine hydrochloride, caused physical and chemical instability problems. The use of non-ionic surface active agents in the formulations unexpectedly overcome these stability problems and provide an elegant stable topical cream product. The amount of non-ionic surfactant in the above compositions range from about 0.1 to about 10 wt % of the total composition.
Non-ionic surfactant
Bhagwat Dileep
Glassman Brad P.
Glassman Daniel
Bradley Pharmaceuticals, Inc.
Criares Theodore J.
Kim Jennifer
Merchant & Gould P.C.
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