The purpose of this study is to determine whether the investigational lotion is an effective treatment of moderate to severe plaque psoriasis in comparison to an approved cream.

Inclusion Criteria:

• Subjects are male or non-pregnant female; 18 years of age at the time of screening.
• Subjects provide Institutional Review Board (IRB) approved written informed consent for participating in this study.
• Subjects have a clinical diagnosis of stable plaque psoriasis involving a minimum of 20% body surface area and an Overall Disease Severity (ODS) score on the designated treatment area of at least 3 as determined by the evaluating investigator.
• Subjects are willing and able to apply the study medication as directed, comply with study instructions and commit to all follow-up visits for the duration of the study.
• Women of childbearing potential (WOCBP) must have a negative urine pregnancy test at the Screening (Part B) and Baseline Visits and agree to use an effective form of birth control for the duration of the study (abstinence, stabilized on oral contraceptives or contraceptive patches for at least three months, implant, injection, IUD, NuvaRing®, condom and spermicidal or diaphragm and spermicidal). Abstinence is an acceptable form of birth control for subjects who are not sexually active. Subjects who become sexually active during the trial must agree to use an effective, non-prohibited form of birth control for the duration of the study.

Exclusion Criteria:

• Subjects have spontaneously improving or rapidly deteriorating plaque psoriasis, or have guttate, pustular, erythrodermic or other non-plaque forms of psoriasis.
• Subjects have a physical condition which, in the Investigator's opinion, might impair evaluation of plaque psoriasis, adrenal axis function (e.g., Addison's Disease, Cushing's Syndrome) or which exposes the subject to an unacceptable risk by study participation.
• Subjects have used any phototherapy (including laser), photo-chemotherapy or systemic psoriasis therapy including methotrexate, retinoids, cyclosporine or biologics within 30 days prior to the initiation of study medication treatment.
• Subjects have used systemic corticosteroids (including oral or intramuscular) or topical, inhaled or intranasal corticosteroids within 30 or 14 days, respectively, prior to Part B of the Screening Visit and/or subjects have used systemic or topical corticosteroids between the Screening Visit and the initiation of treatment.
• Subjects have had prolonged exposure to natural or artificial sources of ultraviolet radiation within 30 days prior to the initiation of treatment or are intending to have such exposure during the study that is thought by the Investigator to likely modify the subject's disease.
• Subjects have used topical psoriatic therapy including tar, anthralin, retinoids, vitamin D analogs (e.g., Dovonex®) within 14 days prior to the initiation of study medication treatment.
• Subjects have used emollients/moisturizers on areas to be treated within one day prior to the initiation of study medication treatment.
• Subjects are currently using lithium or plaquenil.
• Subjects are currently using a beta-blocking medication (e.g., propanolol) or angiotensin converting enzyme (ACE) inhibitors at a dose that has not been stabilized, in the opinion of the Investigator.
• Subjects have a history of sensitivity to any of the ingredients in the study medication.
• Subjects are pregnant, nursing or planning a pregnancy during the study period.
• Subjects are currently enrolled in an investigational drug or device study.
• Subjects have received an investigational drug or an investigational device within 30 days prior to screening.
• Subjects have been previously enrolled in this study and treated with the study medication.
• Subjects have irregular sleep schedules or work night shifts (cortisol levels exhibit physiological diurnal variation).
• Subjects have a screening CST with a post 30-minute stimulation cortisol level of ≤ 18 µg/dL.