Development of artemether-loaded nanostructured lipid carrier (NLC) formulation for topical application.

NLC topical formulation as an alternative to oral and parenteral (IM) delivery of artemether (ART), a poorly water-soluble drug was designed. A Phospholipon 85G-modified Gelucire 43/01 based NLC formulation containing 75% Transcutol was chosen from DSC studies and loaded with gradient concentration of ART (100-750 mg). ART-loaded NLCs were stable (-22 to -40 mV), polydispersed (0.4-0.7) with d90 size distribution range of 247-530 nm without microparticles up to one month of storage. The encapsulation efficiency (EE%) for ART in the NLC was concentration independent as 250 mg of ART loading achieved ∼61%. DSC confirmed molecular dispersion of ART due to low matrix crystallinity (0.028J/g). Ex vivo study showed detectable ART amounts after 20h which gradually increased over 48h achieving ∼26% cumulative amount permeated irrespective of the applied dose. This proves that ART permeates excised human epidermis, where the current formulation served as a reservoir to gradually control drug release over an extended period of time. Full thickness skin study therefore may confirm if this is a positive signal to hope for a topical delivery system of ART.