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