A 12 Day Study To Evaluate A Topical Drug To Treat Plaque Psoriasis

Inclusion Criteria: * Healthy male and/or female subjects age 18 years and older, inclusive. Healthy is defined as no clinically relevant abnormalities identified by a detailed medical history, full physical examination, including blood pressure and pulse rate measurement, 12 lead ECG or clinical laboratory tests. * Subjects with psoriasis vulgaris in a chronic stable phase and with a plaque area of mild to moderate severity sufficient for six treatment fields located in up to three plaque areas. * The target lesion(s) should be on the trunk or extremities (excluding palms/soles). Psoriatic lesions on the knees or elbows are not to be used as a target lesion. Exclusion Criteria: * Subjects with psoriasis guttata, psoriasis punctata, psoriasis erythrodermatica, psoriasis arthropathica and pustular psoriasis. * Treatment with any systemic medications which in the opinion of the investigator might counter or influence the trial aim (including anti psoriasis medications, eg, corticosteroids, cytostatics or retinoids) or medications which are known to provoke or aggravate psoriasis (eg, beta blocker, anti malarial drugs, lithium) or phototherapy/psoralen+UVA (PUVA) within 4 weeks preceding the treatment phase of the trial and during the trial. * Treatment with any locally acting medications (including anti-psoriasis medications like vitamin D analogues, dithranol) within 4 weeks of the treatment phase.