This invention generally relates to an improved method of treating keratosis and is particularly directed to novel nail polish compositions for use in such improved method. It is an object of the invention to provide an im¬ proved method of treating keratosis with a nail polish com¬ position which reduces the moisture exchange between the skin and the environment.

In the practice of the present invention, at least one corrosive agent is incorporated into a nail polish vehi¬ cle which is applied over the area affected by keratosis. The application of the nail polish composition is a simple covering of the affected area by brushing, smearing, or painting. The composition dries quickly to form a fairly durable cover.

The present invention contemplates the use of a corrosive agent which gradually wears away the keratotic lesion by chemical action. A suitable corrosive agent is identified by its corrosive, inflammatory, and irritating action on the affected area of the skin. The corrosive agent must also be non-toxic and otherwise pharmaceutically acceptable. Exemplary corrosive agents include acids, in particular, those carboxylic acids which are pharmaceuti¬ cally acceptable.. In particular, the following chemicals are known corrosive agents and are preferred for use in the invention: ascorbic acid, glacial acetic acid, lactic acid, salicylic acid, trichloroacetic acid, calcium pantothenate, zinc chloride, and podophyllum resin. The present invention

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contemplates the use of other known corrosive agents as well.

The corrosive agent incorporated in the nail pol¬ ish composition is present in an amount effective to re- lieve the keratotic condition with periodic application. More than one corrosive agent may be included in the nail polish composition. Preferably, each corrosive agent is present in an amount between about 1% and 40% of the total weight ^' of the composition. A more preferred range for each corrosive agent in the composition is an amount between 1% and 20% of the total weight.

The present invention contemplates the use of any commercial nail polish, colored or clear, as a vehicle for the corrosive agent. It is critical, however, that the se- lected nail polish form an occlusion over the affected area when dry. Although Revlon (R.T.M.) and Cutex (R.T.M.) nail polishes are used in the examples below, these nail polishes are for illustrative purposes only and are not intended as a limitation. Having described the invention in general terms, the following examples are set forth to more fully illus¬ trate the preferred embodiments of the invention. These ex¬ amples, however, are not meant to be limiting. It is possi¬ ble to produce still other embodiments without departing from the inventive concept herein disclosed. Such emb.odi- ments are within the ability of one skilled in the art.

Example 1 A nail polish composition useful in treating kera¬ tosis was prepared by mixing salicylic acid with Revlon (R.T.M.) clear nail polish in the amount of 1% by total weight and painting a wart on the foot of an 11 year old boy every 48 hours for 3 weeks with the composition. Unexpec¬ tedly, all signs of the wart disappeared with this treatment regimen.

Example 2 A nail composition was prepared by mixing salicylic acid in Cutex (R.T.M.) clear nail polish in the amount of 5%

by weight. The composition was applied to 5 warts on the hands of a 7 year old girl once daily for 2 weeks. Once again, the warts flattened and disappeared over this period with only one wart requiring freezing of the base. Example 3

A nail polish composition was prepared by mixing salicylic acid in Revlon (R.T.M.) clear nail polish in the amount of 20% by weight and the resulting composition was applied to a corn on the lateral surface of the left foot of a 37 year old woman. Unanticipated results were ob¬ tained. With similar applications made every 48 hours for 2 weeks, the corn totally disappeared.

Example 4 A nail polish composition was prepared by mixing lactic acid into Revlon (R.T.M.) clear nail polish in the amount of 10% by weight and the resulting composition was applied once daily to a wart one cm. in diameter on the right hand of a 10 year old boy. A wart of the same size on the left hand was treated similarly with a daily applica- tion of a second nail polish composition which incorporated by weight 16% lactic acid and 16% salicylic acid in Revlon (R.T.M.) clear nail polish. After two weeks of treatment, the wart on the right hand disappeared and although the wart on the left hand nearly disappeared, some traces of the wart still remained which required additional treatment be¬ fore disappearing completely.

Example 5 A nail polish composition was prepared by mixing lactic acid in Cutex (R.T.M.) clear nail polish in the amount of 5% by weight and the resulting composition was applied 3 times weekly to a callus on the sole of the foot of a 38 year old male. Unforeseen, the callus disappeared within 10 days.

Example 6 A nail polish composition was prepared by mixing glacial acetic acid in Revlon (R.T.M.) clear nail polish in

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the amount of 5% by weight and the resulting composition was applied once daily to 8 warts on the hands and elbows of a 24 year old female. Wholly unexpected results were ob¬ tained. Within 3 weeks, no trace of the warts remained. Example 7

A nail polish composition was prepared by incorpo¬ rating by weight 10% lactic acid and 10% salicylic acid in Revlon (R.T.M.) clear nail polish and the resulting composi¬ tion was applied every other day to a large plantars wart on the sole of an 11 year old boy. After 21 days of such ther¬ apy, the wart was nearly disappeared. After freezing the base, the plantars wart never recurred.

Example 8 A nail polish composition was prepared by mixing 15% lactic and 15% glacial acetic acid by weight in Revlon (R.T.M.) clear nail polish. The composition was applied once daily to calluses on the palms of a 38 year old man. After 1 week of such treatment the calluses disappeared.

Example 9 A nail polish compositon was prepared by mixing 5% salicylic acid, 5% lactic acid and 5% glacial acetic acid by weight in Cutex (R.T.M.) clear nail polish and the resulting composition was applied once every 48 to 72 hours to a corn on the big toe of a 30 year old female. Unexpectedly, the corn disappeared after 2 weeks of treatment.

Example 10 A nail polish composition was prepared by mixing 20% lactic acid and 20% glacial acetic acid by weight in Revlon (R.T.M.) clear nail polish and the resulting composi- tion was applied once every three days to a wart on the dor- sum of the right hand of a 13 year old girl. Although the skin surrounding the wart became mildly irritated, the wart disappeared within 2 weeks of treatment.

As demonstrated by these examples, this invention provides an improved method and composition for treating keratosis. The occlusion formed by the nail polish composi¬ tion over the affected area reduces the moisture exchange

between the skin and the environment. The durability of the nail polish composition covering the affected area al¬ lows for prolonged contact with the corrosive agent. For these reasons, the activity of the corrosive agent on the keratotic condition is increased, with fewer applications of the corrosive agent.

These examples also show that the present invention provides a method for relieving keratosis which is relative¬ ly painless, easy and convenient for both children and adults to use because of its simplicity. Furthermore, the invention is relatively inexpensive and would be affordable by the general public.

While there has been described what is at present considered to be the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein, without de¬ parting from the invention.

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