Chaulmoogra oil based methotrexate loaded topical nanoemulsion for the treatment of psoriasis

Chaulmoogra oil based methotrexate loaded nanoemulsion was prepared via emulsification technique using tween 80 and ethanol as surfactants. The formulation was characterized by FTIR and TEM. The prepared nanoemulsion has an average particle size of 34 nm with negative surface charge and has pH compatible to skin. Rheological studies revealed the shear thinning non-Newtonian visco-elastic behavior of the formulation as explained by the Herschel Bulkley model. The formulation was cytocompatible towards mouse dermal fibroblast L929 cells when tested by MTT assay and was stable in refrigerator for the tested period of 3 months. The in-vitro release mechanism of methotrexate from formulation followed zero order release kinetics with non Fickian diffusion mechanism. The ex-vivo skin permeation studies done by Franz diffusion cell apparatus using porcine skin revealed the improved skin permeation and retention of drug in deep skin layers when compared with control drug solution. The in vivo anti-psoriatic studies done on imiquimod psoriatic model revealed superior anti-psoriatic efficacy, with effective skin retention and lesser serum and tissue accumulation when compared with orally administered methotrexate tablet.