Novel transdermal bioadhesive surfactant-based system for release and solubility improvement of antimalarial drugs artemether-lumefantrine.

Artemether (ART) and lumefantrine (LUM) are the gold standard antimalarial drugs used for the treatment of malaria in children and pregnant women. Typically, ART and LUM are delivered orally in the form of a combined tablet, however, the appropriateness of this route of administration for these drugs is questionable due to the poor absorption and therefore bioavailability observed unless administered alongside lipid-rich foods. Transdermal drug delivery in the form of a patch-type system has been identified as a viable alternative to the conventional tablet-based therapy. A novel, surfactant-based ART-LUM formulation (S3AL), developed for transdermal delivery, may eliminate the shortcomings associated with oral delivery; namely poor drug absorption which is caused by the inherently low solubility of ART and LUM. Moreover, by successfully delivering these antimalarials transdermally, first-pass metabolism will be avoided leading to enhanced drug bioavailability in both cases. The S3AL formulation contained ART and LUM at equal concentrations (2.5% w/w of each) as well as Procetyl® AWS (30% w/w), oleic acid (10% w/w), 1-methyl-2-pyrrolidone (10% w/w), and water (45% w/w). The addition of LUM to the formulation changed the system from a striae structure to a dark field structure when visualized by a polarized light microscope. Additionally, this system possessed higher viscosity and superior skin bioadhesion, as evidenced by mechanical characterization, when compared to a similar formulation containing ART alone. S3AL was also proven to be biocompatible to human keratinocyte cells. Finally,in vitrostudies demonstrated the propensity of S3AL for successful delivery via the transdermal route, with 2279 ± 295 µg cm-2of ART and 94 ± 13 µg cm-2of LUM having permeated across dermatomed porcine skin after 24 h, highlighting its potential as a new candidate for the treatment of malaria.

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 106Plasmodium 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.

Semisynthetic Derivative of Artemisia annua-Loaded Transdermal Bioadhesive for the Treatment of Uncomplicated Malaria Caused by Plasmodium falciparum in Children.

According to the most recent World Health Organization statistics, malaria infected approximately 219 million people in 2017, with an estimate of 435,000 deaths (World Health Organization, 2018). Communities isolated from cities are the most deprived of access to the necessary hospital facilities. Herein we report the development of a transdermal bioadhesive containing artemether (ART), an alternative, potentially lifesaving, treatment regimen for malaria in low-resource settings. Bioadhesives were prepared from an aqueous blend of hydroxyethylcellulose (4.5% w/w), ART, propoxylated-ethoxylated-cetyl-alcohol, polysorbate 80, propyleneglycol, glycerine, mineral oil, and oleic acid. In this study, the average pore size of bioadhesive 5.5b was 52.6 ± 15.31 µm. Differential scanning calorimetry and thermogravimetric analyses confirm the thermal stability of ART bioadhesives at room temperature. Tensile tests indicated good mechanical properties for bioadhesive 5.5b, when compared to 5.5a, where 5.5b showed elastic modulus 0.19 MPa, elongation at break 204%, tensile stress 0.31 MPa, tensile strength at break 0.23 MPa. Bioadhesion assays suggested that formulations containing surfactants had higher detachment forces. Permeation studies demonstrated that the best outcome was achieved with a bioadhesive containing 25 mg ART (5.5b) that after 24 h released 6971 ± 125 µg, which represents approximately 28% of drug permeation. Data reported presents a promising candidate for a new antimalarial transdermal formulation.

Protective capacity of Artemisia annua as a potent antioxidant remedy against free radical damage

Objective: To evaluate the antioxidant capacity of four leaf-derived solvent extracts of Artemisiaannua Methods: A. annua leaves were extracted with four solvents (absolute ethanol, absolute methanol, 70% ethanol and 70% methanol), and extracts obtained studied by five complementaryin vitro antioxidant test systems using ascorbic acid (vitamin C) and rutin as standard references. Results: The extracts remarkably inhibited lipid peroxidation (79.81%-86.70%), and erythrocyte haemolysis (40.02%-49.91%). Their IC50 values for hydroxyl, nitric oxide and hydrogen peroxide radical scavenging activities ranged from 2.39-3.81 mg/mL (superior to the standards), 107.24-144.49 μg/mL and 28.53-53.20 μg/mL, respectively. 70% alcohol extracts generally showed better antioxidant activity than absolute alcohol extracts. (A. annua), a medicinal plant widely touted for its vast phyto-therapeutic potential. Conclusions: The results indicate that A. annua leaf extracts have potent antioxidant activities that would have beneficial effect on human health, and aqueous organic solvents are superior to the absolute counterparts in yielding extracts with better antioxidant potential.