Development, characterization and evaluation of topical methotrexate-entrapped deformable liposome on imiquimod-induced psoriasis in a mouse model.

The aim of this study was to prepare and characterize topical methotrexate (MTX) with different percentages (0.05%, 0.1%, 0.25% and 0.5%) entrapped in deformable liposomes using phosphatidylcholine and oleic acid. The effectiveness and sub-acute toxicity of these topical formulations were investigated in imiquimod (IMQ)-induced psoriasis in a mouse model (IMQP). The particle sizes of formulations were around 100 nm with a mean zeta potential of -72.87 mV. The entrapment efficiency (EE%) of MTX in liposomal formulations were more than 85%. Franz cell permeability studies indicated that permeation of MTX through the healthy BALB/c mice skin is very low; however, in the inflammatory skin, which was induced by IMQ it was significant (50%). Liposomal MTX (LM 0.05 and 0.1%) caused significant reduction of thickness score dose-dependently in IMQP compared to the injected MTX. Moreover, investigation of the inflammatory factor and pathological examinations of skin proved the superiority of the LM treating group. Pathological examinations also showed there are no toxicity in organs of the mice that received the LM. Blood cell count test didn't show any abnormality. MTX-entrapped deformable liposomes could be a topical option in future for the treatment of human psoriasis with a less toxicity and merit further investigations.