Pharmaceutical NanotechnologyDevelopment 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 (0.028 J/g). Ex vivo study showed detectable ART amounts after 20 h which gradually increased over 48 h 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.

Artemether is thermostable at 90-95 °C, so has been stably formulated in well selected nanostructured lipid carriers as an alternative sustained release topical regimen devoid of the drug's extensive nausea-vomiting effect which majorly account for patient non-compliance aside from some contra-indications. Ex vivo study has shown that ART permeates through human excised skin which is known to mimic permeation in vivo.204