Title:  Compositions and methods for enhancing corticosteroid delivery

United States Patent:  6,765,001

Issued:  July 20, 2004

Inventors:  Gans; Eugene H. (Westport, CT); Wortzman; Mitchell S. (Scottsdale, AZ)

Assignee:  Medicis Pharmaceutical Corporation (Scottsdale, AZ)

Appl. No.:  037360

Filed:  December 21, 2001

Abstract

The present invention comprises a composition, method of enhancing potency and method of delivering corticosteroids in a vehicle comprising at least two penetration enhancers, and solvents and emulsifiers. The propylene glycol and penetration enhancers are present in ratio to the total of the propylene glycol, penetration enhancers, and solvents and emulsifiers of at least about 0.70.

SUMMARY OF THE INVENTION

The present invention comprises a novel vehicle which is safe for topical application, stable, and provides increased potency for corticosteroid preparations, especially fluorinated corticosteroids.

An embodiment of the present invention delivers the corticosteroid in a vehicle that comprises a corticosteroid, and (a) at least two penetration enhancers, including propylene glycol, dimethyl isosorbide or diisopropyl adipate, (b) solvents and/or emulsifiers for the corticosteroid and optionally the penetration enhancers and (c) optionally, non-solvent/emulsifier ingredients. The vehicle has a ratio of a:(a+b) that is greater than or equal to 0.70, preferably greater than or equal to 0.80 and most preferably greater than or equal to 0.90 or 0.95.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention enhances the potency of corticosteroid preparations with a vehicle comprising at least two penetration enhancers, including diisopropyl adipate, dimethyl isosorbide, propylene glycol, 1,2,6-hexanetriol, and benzyl alcohol. The corticosteroids with which this invention may be used include, but are not limited to, fluorinated corticosteroids.

Another embodiment of the present invention is a method for enhancing the potency of corticosteroids, preferably fluorinated corticosteroids. The corticosteroid is combined with two or more penetration enhancers (preferably propylene glycol and at least one other penetration enhancer), and one or more solvents and emulsifiers for the corticosteroid and optionally penetration enhancers, wherein the penetration enhancers are present in ratio to the total of the penetration enhancers, and solvents and emulsifiers of at least about 0.70, preferably at least 0.80 and most preferably 0.90 or 0.95. Optionally, one or more inactive ingredients may also be combined with the corticosteroid.

Another embodiment of the present invention is a method of delivering corticosteroids to skin, nails or hair, preferably mammalian skin, most preferably human, dog or cat skin. The corticosteroids are preferably fluorinated corticosteroids. The corticosteroid is combined with two or more penetration enhancers, and one or more solvents and emulsifiers for the corticosteroid, wherein the penetration enhancers are present in ratio to the total of the penetration enhancers, and solvents and emulsifiers of at least about 0.70, preferably at least 0.85 and most preferably 0.90 or 0.95. Optionally, one or more inactive ingredients may also be combined with the corticosteroid.

As indicated above, this invention is broadly applicable to corticosteroids in general, and fluorinated corticosteroids in particular, most preferably fluocinonide or fluocinolone acetonide. The following examples show its application to preparations of fluocinonide, a commonly used fluorinated corticosteroid. Fluocinonide is a corticosteroid which is the 21-acetate ester of fluocinolone acetonide with the chemical name pregna-1,4-diene-3,20-dione,21-(acetyloxy)-6,9-difluoro-11-hydroxy-16, 17-[(1-methylethylidene)bis(oxy)]-,(6.alpha.,11.beta., 16.alpha.)-. Compositions containing 0.05% (all percentages are weight percentages) fluocinonide are commonly classified as Class 2.

EXAMPLE 1

Experiments were conducted with embodiments of the present invention and several control compositions. Compositions were prepared and the investigator was blinded with respect to the compositions. Thirty-six healthy volunteers were enrolled for two-day trials. On day 1, a single application of approximately 10 milligrams of at least eight compositions was made to 1 cm² sites on the lower aspect of each volunteer's forearms in accordance with a computer generated randomization code. After applying the compositions, the sites were protected using a raised perforated guard. The guard was secured to the arm with a non-occlusive tape and the subjects were scheduled to return the following day after being instructed to keep the sites dry.

After approximately 16 hours of contact with the skin, the protective guards were removed and the compositions were removed from the test sites by gently washing with mild soap and water. Skin vasoconstrictor evaluations were performed on a four point scale (0-3) at approximately 18 hours after application.

Scores for skin vasoconstriction were summed for each composition (each composition was applied to thirty-six volunteers and those thirty-six scores were summed). For each composition tested, the ratio of penetration enhancers (a) to the sum of penetration enhancers, and solvents and emulsifiers (a+b) was calculated (a:(a+b)). All of the compositions comprise 0.10% fluocinonide.

As seen in the above table, the average vasoconstrictor scores are significantly lower for ranges of a:(a+b)<0.70. The corticosteroid preparations with average vasoconstrictor scores of 58 and 62 are significantly less potent than those preparations with average vasoconstrictor scores of 72 and higher. Scores of 62 and 58 are not significantly different. This magnitude of increase in vasoconstrictor scores is typical of an increase in class.

Several control compositions (with 0.10% fluocinonide and no penetration enhancers, as defined below, were included) were also tested for their vasoconstrictor scores in the same manner. Therefore, the ratios of a:(a+b) are zero. The vasoconstrictor scores are 60.00 and 59.00, which are significantly lower than the present invention's embodiments' vasoconstrictor scores.

Additionally, several other control compositions were tested for their vasoconstrictor scores ("vasoscores"). These compositions comprised 0.10% fluocinonide, and no diisoproyl adipate, propylene glycol or dimethyl isosorbide. Their vasoscores were 49.00, 47.00 and 44.00.

The experiments also included several Class 1 compositions as comparison points. Psorcon.RTM. ointment by Dermik Laboratories, Inc. of Collegeville, Pa. with 0.05% diflorasone diacetate had a vasoscore of 101. Ultravate.RTM. ointment by Westwood-Squibb of Evansville, Ind. with 0.05% halobetasol propionate had a vasoscore of 97, while Ultravate.RTM. cream by Westwood-Squibb with 0.05% halobetasol propionate had a vasoscore of 92.

In the ratio of (a): (a+b), penetration enhancers include at least two of: propylene glycol, diisopropyl adipate, dimethyl isosorbide, 1,2,6 hexanetriol, and benzyl alcohol (collectively referred to as "a"). The solvents and emulsifiers for the corticosteroid include one or more of dehydrated alcohol, alcohol (95% v/v) USP, 3-Cyclohexene-1-Methanol, .varies.4-Dimethyl-a-(4-Methyl-3-Pentenyl)-, Steareth-2, Steareth-21, citric acid, CPE-215, diisopropanolamine (1:9), DIPA/PG (1:9), ethoxydiglycol, Potassium hydroxide (10%), PEG-40 Stearate, PEG-7000, Polysorbate 60, potassium hydroxide (1%), propylene carbonate USP, propylethylene glycol 4, oleyl alcohol, sodium lauryl sulfate, sorbitan monostearate, sorbitan stearate, and 1,2,3-Propanetriol Ester (collectively referred to as "b").

The compositions optionally comprise non-solvent/emulsifier ingredients, such as Glyceryl Stearate (and) PEG-100 Stearate, carbopol 980, cyclomethicone NF, glyceryl monostearate, hydroxyethyl cellulose, hydroxypropyl cellulose, isopropyl myristate, methyl paraben NF, mineral oil, oleic acid NF, PEG-100 Stearate, petrolatum, propyl paraben NF, purified water, stearyl alcohol, white petrolatum, and white wax.

The combination of penetration enhancers used in the invention have a remarkable and unexpected result. Compounds using similar concentrations of a single penetration enhancer (e.g. propylene glycol as the sole penetration enhancer with 0.10% fluocinonide yielded vasoscores of 72.00, and 50.00, depending on the solvents, emulsifiers and non-solvent/emulsifier ingredients used) do not have similarly high vaso scores. Compositions with the combination of penetration enhancers and formula scores of less than 0.65 also have low vaso scores. Therefore the invention results in an unexpected increase in potency of the fluocinonide.

EXAMPLE 2

One embodiment of the present invention is detailed in the chart below.

EXAMPLE 3

Another embodiment of the present invention is detailed in the chart below.

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, that the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are evident from a review of the following claims.

Claim 1 of 17 Claims

What is claimed is:

1. A composition comprising

One or more corticosteroids, wherein one corticosteroid comprises fluocinonide;

Two or more penetration enhancers selected from the group consisting of diisopropyl adipate, dimethyl isosorbide, propylene glycol, 1,2,6-hexapetriol, and benzyl alcohol; and

one or more of the group consisting of solvents and emulsifiers, wherein the penetration enhancers are present in a ratio to a total of the penetration enhancers, and solvents and emulsifiers of at least about 0.90.

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