Anti-psoriatic and toxicity evaluation of methotrexate loaded chitin nanogel in imiquimod induced mice model.

Methotrexate loaded chitin nanogel (MCNG) was formulated for its topical use in psoriasis. MCNG was characterized by DLS, TEM and FTIR. The MCNG particles were spherical in shape with size of 196±14nm, having surface charge of +9.21±0.42 mv. MCNG exhibited greater swelling and drug release at acidic pH than neutral and alkaline conditions. The treatment with MCNG showed significant level of toxicity on HaCaT and THP-1 cells and was taken up well by HaCaT cells as revealed by fluorescent microscopy. MCNGs exhibited significant anti-inflammatory activity as revealed by the inhibitory effects observed on the activity of COX-2 and LOX-5 enzymes expressed in THP-1 cells. Skin permeation studies revealed an increased trasdermal flux of methotrexate from MCNG with loosened stratum corneum and other epidermal layers of skin in comparison with control methotrexate solution treated samples. Significant anti-psoriatic efficacy on imiquimod (IMQ) induced model of psoriasis without any dermal and systemic toxicities suggest that it as an ideal delivery platform for topical delivery of methotrexate in psoriasis. Thus it is expected to become a better alternative for the oral delivery of methotrexate in the selected disease.