Photocil is a topical drug (cream) that selectively delivers Narrow Band - Ultraviolet B (NB-UVB) therapy when exposed to sunlight. Photocil is intended to help protect users from non-therapeutic Ultraviolet B (UVB) radiation while selectively passing wavelengths of light in the NB-UVB range with peak transmission of 308nm. The aim of the study is to assess the safety and efficacy of Photocil in the treatment of psoriasis

NB-UVB phototherapy is a common treatment for patients with psoriasis, and has been reported to be safe and effective in numerous clinical trials. Clinical trials have reported achievement of Psoriasis Area Severity Index (PASI)-75 in 50-70% of patients after 4-6 weeks of NB-UVB treatment.

Many drawbacks limit patients compliance, access, and acceptance of traditional NB-UVB phototherapy. The strict treatment regimen (2-3 sessions per week for an average of 12 weeks or more) performed at a specialized phototherapy clinic combined with high cost and low or no reimbursement make compliance and access a major drawback.

In order to address the drawbacks of phototherapy, we developed a novel topical cream - Photocil - that selectively delivers NB-UVB therapy when exposed to sunlight. When used with natural sunlight, Photocil provides a convenient alternative to traditional clinic based phototherapy; thus, has the potential to dramatically increase patient compliance and treatment outcome.

Inclusion Criteria:

• Diagnosed with psoriasis vulgaris confirmed by a dermatologist
• Psoriasis lesions affecting at a minimum 5% of the facial, legs, or arms surface area
• Age: 18 to 65
• Participants able to give informed consent

Exclusion Criteria:

• Subject did not respond to prior phototherapy treatment
• Subject completed phototherapy for same lesion(s) in last 6 months
• Subject has previous history of skin cancer
• Subject has previous history of photosensitivity
• Subject has a history of herpes (HSV I or II) outbreaks
• Subject has previous history of autoimmune disease may be excluded at investigator's discretion
• Subject is currently taking of immunosuppressive or photosensitizing drugs
• Subject plans to use antibiotics, anti-fungal, calcineurin inhibitors or other drugs that may cause photosensitivity during the study period. These patients may be excluded at investigator's discretion
• Subject is pregnant or lactating women