Preparation and Characterization of Inhalable Ivermectin Powders as a Potential COVID-19 Therapy
Ivermectin has received worldwide attention as a potential COVID-19 treatment after showing antiviral activity against SARS-CoV-2 in vitro. However, the pharmacokinetic limitations associated with oral administration have been postulated as limiting factors to its bioavailability and efficacy. These limitations can be overcome by targeted delivery to the lungs. In this study, inhalable dry powders of ivermectin and lactose crystals were prepared and characterized for the potential treatment of COVID-19.
Methods: Ivermectin was co-spray dried with lactose monohydrate crystals and conditioned by storage at two different relative humidity points (43% and 58% RH) for a week. The in vitro dispersion performance of the stored powders was examined using a medium-high resistance Osmohaler connecting to a next-generation impactor at 60L/min flow rate. The solid-state characteristics including particle size distribution and mor- phology, crystallinity, and moisture sorption profiles of raw and spray-dried ivermectin samples were assessed by laser diffraction, scanning electron microscopy, Raman spectroscopy, X-ray powder diffraction, thermo- gravimetric analysis, differential scanning calorimetry, and dynamic vapor sorption.
Results: All the freshly spray-dried formulation (T0) and the conditioned samples could achieve the anticipated therapeutic dose with fine particle dose of 300 lg, FPFrecovered of 70%, and FPFemitted of 83%. In addition, the formulations showed a similar volume median diameter of 4.3 lm and span of 1.9. The spray-dried formulations were stable even after conditioning and exposing to different RH points as ivermectin remained amorphous with predominantly crystalline lactose.
Conclusion: An inhalable and stable dry powder of ivermectin and lactose crystals was successfully formulated. This powder inhaler ivermectin candidate therapy appears to be able to deliver doses that could be safe and effective to treat the SARS-COV-2 infection. Further development of this therapy is warranted.
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Preparation and Characterization of Inhalable Ivermectin Powders as a Potential COVID-19 Therapy
Ahmed H. Albariqi, Wei-Ren Ke, Dipesh Khanal, Stefanie Kalfas, Patricia Tang, Warwick J Britton, John Drago, and Hak-Kim Chan – Journal of Aerosol Medicine and Pulmonary Drug Delivery – https://doi.org/10.1089/jamp.2021.0059
Materials
GMP-grade ivermectin raw powder was received from Hovione PharmaScience Ltd. (Tapa, Macau). Lactohale® 300 (LH300, alpha-lactose monohydrate) was supplied from DFE Pharma (Goch, Germany); potassium chloride, sodium bromide, and silica gel from Sigma-Aldrich Co. (St. Louis, MO, USA); potassium carbonate anhydrous from Fluka Chemie AG (Buchs, Switzerland), acetonitrile and methanol from Merck KGaA (Darmstadt, Germany), and isopropyl alcohol (IPA) from Sigma-Aldrich Pty Ltd. (Sydney, Australia). The water used in chemical assays was purified with an SG ultrapure water system (Barsbüttel, Germany).