Application of Statistical Designs in the Formulationof Lipid Carriers of Methotrexate

Methotrexate (MTX) being the widely used biologic agent is used to treat severe and/or disabling psoriasis but precipitates various side effects on oral therapy. Encapsulating methotrexate in flexible liposomes for delivery through skin could lead to better therapeutic action and reduce side effects. In order to screen out the various factors during liposome formulation development, Plackett Burman screening design was applied. Three formulation variables and eight process variables were identified and one factor plot was used to predict the response. The present study was aimed at identifying the important factors among the various factors, which could attribute to obtain highest drug entrapment during formulation of flexible liposomes. Results obtained proved that application of a screening design such as Plackett-Burman design efficiently identified the most significant factors. Identified significant factors were further optimized using Central Composite Design using the software Design Expert v 6.0. Three optimal solutions suggested by the design were characterized for entrapment efficiency, particle size, zeta potential and microscopical analysis. Results demonstrate the feasibility of applying statistical designs in the development of flexible liposomes of methotrexate.