A Study to Determine the Efficacy and Safety of Halobetasol Propionate Lotion 0.05% in Subjects With Plaque Psoriasis

Inclusion Criteria: 1. Subject is Male or non-pregnant female; 18 years of age at time of Screening. 2. Subject is willing and able to give written informed consent. 3. subject is willing and able to apply the test article(s) as directed, comply with study instructions and commit to all follow-up visits for the duration of the study. 4. Subject has a clinical diagnosis of stable plaque psoriasis involving a minimum of 2% and no more than approximately 10% body surface area (BSA) (excluding the face, scalp, groin, axillae and other intertriginous areas). 5. Subject has an Overall Disease Severity (ODS) score for the Treatment Area of at least three (3) at the Baseline Visit. 6. If subject is a woman of childbearing potential (WOCBP) , she must have a negative urine pregnancy test (UPT) and agree to use an effective form of birth control for the duration of the study (i.e., abstinence, stabilized on hormonal contraceptives \[oral, injectable, transdermal or intravaginal\] or IUD for at least three months prior to test article application, condom and a spermicidal, or diaphragm and a 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 form of birth control for the duration of the study. Exclusion Criteria: 1. Subject has spontaneously improving or rapidly deteriorating plaque psoriasis. 2. Subject has guttate, pustular, erythrodermic or other non-plaque forms of psoriasis. 3. Subject has a physical condition which, in the investigator's opinion, might impair evaluation of plaque psoriasis, or which exposes the subject to an unacceptable risk by study participation. 4. Subject has used any phototherapy (including laser), photo-chemotherapy or systemic corticosteroid therapy (such as systemic corticosteroids \[including intralesional, intra-articular, and intramuscular corticosteroids\]) within 30 days prior to the Baseline Visit. 5. Subject has used any systemic methotrexate, retinoids, cyclosporine or analogous products within 90 days prior to the Baseline Visit. 6. Subject has used any systemic biologic therapy (i.e., FDA approved or experimental therapy) within five (5) half-lives of the biologic prior to the Baseline Visit. Published or documented half-life of the product provided by the commercial supplier or Sponsor should be used to establish this value. 7. Subject had prolonged exposure to natural or artificial sources of ultraviolet radiation within 30 days prior to the Baseline Visit or is intending to have such exposure during the study that is thought by the investigator likely to modify the subject's disease. 8. Subject has used topical body (excluding the scalp) psoriasis therapy including coal tar, anthralin, steroids, retinoids, vitamin D analogs (e.g., Dovonex®) within 14 days prior to the Baseline Visit. 9. Subject has used emollients/moisturizers on areas to be treated within four hours prior to clinical evaluation at the Baseline Visit. 10. Subject is currently using lithium or Plaquenil (hydroxychloroquine). 11. Subject is currently using a beta-blocking medication (e.g., propanolol) or angiotensin converting enzyme (ACE) inhibitor at a dose that has not been stabilized, in the opinion of the investigator. 12. Subject has a history of sensitivity to any of the ingredients in the test article. 13. Subject is pregnant, lactating, or is planning to become pregnant during the study. 14. Subject is currently enrolled in an investigational drug or device study. 15. Subject has used an investigational drug or investigational device treatment within 30 days prior to the Baseline Visit. 16. Subject has been previously enrolled in this study and treated with a test article. 17. Subject is known to be noncompliant or is unlikely to comply with the requirements of the study protocol (e.g., due to alcoholism, drug dependency, mental incapacity) in the opinion of the investigator.