Abstract: Psoriasis is a common and difficult condition to treat. Corticosteroids and other agents are often used. Zinc pyrithione has been used for other related conditions. This study compares the use of combined micronized clobetasol propionate and zinc pyrithione (DermaZinc™ prescription strength) together VS control cream and generic clobetasol propionate alone. The one month study was double-blind controlled with treatments applied on either side of the body in a randomized fashion. There were 36 patients enrolled in the study. Of those, one was disqualified due to possible improper usage of the two test products DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate VS generic Clobetasol Propionate, and three were disqualified due to substantial lapse of time between appointments. The psoriasis was examined for the following parameters: erythema, scaling, and thickness. The results demonstrate that the DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate was significantly more effective than the generic clobetasol propionate alone for each parameter. In addition, the DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate cleared lesions faster compared to generic Clobetasol Propionate. We conclude that there is a synergistic effect of using corticosteroids with zinc pyrithione in the treatment of psoriasis.

Introduction
Psoriasis is a dermatologic condition notable by papulosquamous plaques on the extremities, trunk, and scalp. The plaques are characteristically very thick with marked erythema or "salmon" colored. The scaling on the surface is typically very pronounced and powdery with significant adherence. Psoriasis has been estimated to be prevalent from 1.5% to 2.5% of the total population. The cause of psoriasis is not known. It has been suspected that the psoriasis has an immunological mechanism that causes the lesions.

Topical therapies for psoriasis has included corticosteroids, tars, anthralins and keratolytics. Newer therapies include vitamin D analogs, new anthralin preparations and topical retinoids. Additional therapies include the use of exposure to ultraviolet light, which may be used alone, or as an adjunct to several other therapies.

Zinc pyrithione has been used for a variety of conditions, including seborrheic dermatitis and dandruff. Zinc pyrithione has also been shown in some studies to reduce epidermal proliferation of test animals.

The purpose of the study is to compare the clinical efficacy of combining zinc pyrithione DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate to generic Clobetasol Propionate and to a negative control on the treatment of psoriasis.

Method and Materials
The study was conducted in a double-blind format consisting of the randomized application of either the DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate on one side of the body and on the other side of the body, either the generic Clobetasol Propionate or negative control cream. The patients were accepted into the study with moderate to severe psoriasis with at least 15% body surface area involvement. The lesions had moderate to severe standings in scaling, thickness, and erythema of the psoriatic lesions.

Visits:
The patients were given an instruction sheet and a written psoriasis evaluation. The dermatologist then examined the skin using a standardized psoriatic parameter score sheet. The 35mm photography were taken. The follow-up visit was in one month.

Analysis:
The evaluation form will ask the patient to evaluate the skin with a scale from 0-3. The skin parameters for evaluation will include: scalyness of the lesions, redness of lesions, thickness of the lesions, pruritis, body surface area involved.

A board-certified dermatologist examined the psoriasis for the following characteristics: hyperkeratoses (scaling), erythema, thickness and body surface area affected. The parameters for each characteristic was at 0 to 3 with 0 being no residual amount of the characteristics, 1 being mild amount, 2 being moderate amount, and 3 being severe or marked amount.

Biopsies:
The biopsies were performed on the perilesional region of the psoriasis using standard 3mm biopsy technique and the tissue material will be immediately placed into 10% formalin. The skin was closed with a 5-0 nylon suture to be removed in 7 days.

Results
The double-blind controlled study on the use of DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate, generic Clobetasol Propionate, and control vehicle demonstrated a significant improvement. The study was based on standardized evaluation scores based on erythema, scaling and thickness of the examined lesions. For each parameter, the DermZinc™ Spray compounded with 50mg micronized Clobetasol Propionate improved significantly better than the other products tested.

The DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate improved the evaluations scores for erythema by 1.50, the scaling scores by 1.84, the thickness scores by 1.74, and the overall score of 5.08. The generic Clobetasol Propionate, improved the evaluation scores for erythema by 0.81, the scaling scores by 1.09, the thickness scores by 1.12, and the overall score by 3.02. The control vehicle product improved the evaluation scores for erythema by 0.39, the scaling scores by 0.69, the thickness scores by 0.61, and the overall score by 1.69.

The scores for all the parameters, erythema, scaling, and thickness, and the overall scores were significantly different for the DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate in comparison to the generic Clobetasol Propionate (p<0.05) and to the Control (p<0.02).

Conclusion
The double-blind study clearly demonstrates that the DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate is substantially more effective than generic Clobetasol Propionate for psoriasis over a one month treatment time. From the study, we found that the DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate is one of the most effective single products for psoriasis. The product was significantly more effective in reducing erythema, thickness, scaling, and the overall psoriasis lesion. As expected, the Control Cream was marginally effective. The application of a lotion has been known to be mildly effective for psoriasis. In addition, the generic Clobetasol Propionate was significantly effective in improving psoriasis as has been demonstrated in other studies.

The DermaZinc™ Spray contains synergistic combination of zinc pyrithione and micronized Clobetasol Propionate. The zinc pyrithione probably improves the psoriasis because of its effect on decreasing cell proliferation and has been demonstrated to work on related conditions. There may also be a potentiating benefit of the zinc pyrithione of assisting the Clobetasol Propionate's effect on psoriasis.

Because of the rapid results of DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate, the patient does not need to use potent steroids for as long as other steroid products, increasing the overall therapeutic safety of the topical steroids. More studies will be conducted to evaluate whether DermaZinc™ Spray compounded with 50mg micronized Clobetasol Propionate increases psoriatic remission.