Artemether and lumefantrine dissolving microneedle patches with improved pharmacokinetic performance and antimalarial efficacy in mice infected with Plasmodium yoelii

Malaria affects more than 200 million people annually around the world, killing a child every 2 min. Artemether (ART) and lumefantrine (LUM) are the gold standard choice to treat uncomplicated Plasmodium falciparum malaria; however, they are hydrophobic compounds with low oral bioavailability. Microneedle (MN) arrays consist of micron-sized needles on one side of a supporting base and have the ability to bypass the skin's stratum corneum barrier in a minimally invasive way, creating temporary channels through which drugs can diffuse, including those with poor water solubility. Herein, we report the development of dissolving MNs (DMNs) containing ART (MN-ART) and LUM (MN-LUM) as an alternative treatment regimen for malaria in low-resource settings. To incorporate the drugs into the MNs, nanosuspensions (NSs) for both molecules were developed separately to enhance drug solubility. The NSs were freeze-dried and the powder form was incorporated directly in an aqueous polymeric blend with poly-vinyl-pyrrolidone for MN-ART and a sodium hyaluronate hydrogel for MN-LUM. The in vivo bioavailability studies were performed using a MN reapplication scheme (1 × a day for 3 days), illustrating that an extended-release profile was achieved for both drugs when MNs were applied intradermally, and when compared to conventional oral treatment. The ART-LUM oral treatment was used as a positive control. For antimalarial activity, studies with animals infected with 10⁶ Plasmodium yoelii 17XNL (12 days) were also conducted using female C57BL/6JUnib mice, demonstrating a 99.5% reduction in parasitemia by day 12 post-infection. By abolishing the infection, MN-ART and MN-LUM may serve as a promising controlled intradermal delivery device for antimalarial drugs to be explored in endemic areas.