Design and optimization of topical methotrexate loaded niosomes for enhanced management of psoriasis: application of Box-Behnken design, in-vitro evaluation and in-vivo skin deposition study.

Psoriasis, a skin disorder characterized by impaired epidermal differentiation, is regularly treated by systemic methotrexate (MTX), an effective cytotoxic drug but with numerous side effects. The aim of this work was to design topical MTX loaded niosomes for management of psoriasis to avoid systemic toxicity. To achieve this goal, MTX niosomes were prepared by thin film hydration technique. A Box-Behnken (BB) design, using Design-Expert(®) software, was employed to statistically optimize formulation variables. Three independent variables were evaluated: MTX concentration in hydration medium (X1), total weight of niosomal components (X2) and surfactant: cholesterol ratio (X3). The encapsulation efficiency percent (Y1: EE%) and particle size (Y2: PS) were selected as dependent variables. The optimal formulation (F12) displayed spherical morphology under transmission electron microscopy (TEM), optimum particle size of 1375.00 nm and high EE% of 78.66%. In-vivo skin deposition study showed that the highest value of percentage drug deposited (22.45%) and AUC0-10 (1.15 mg.h/cm(2)) of MTX from niosomes were significantly greater than that of drug solution (13.87% and 0.49 mg.h/cm(2), respectively). Moreover, in-vivo histopathological studies confirmed safety of topically applied niosomes. Concisely, the results showed that targeted MTX delivery might be achieved using topically applied niosomes for enhanced treatment of psoriasis.