Inhalable Antibiotics Manufactured Through Use of Near-Critical or Supercritical Fluids

The development of unit-dose, inhalable, antibiotic microparticles for use in primary and combined therapy approaches to treating tuberculosis (TB), multi-drug-resistant (MDR-TB), and extensively drug-resistant TB is explored using the gentle drying process of Carbon-dioxide Assisted Nebulization with a Bubble Dryer (CAN-BD). The microparticles produced using this method contain capreomycin, kanamycin, and isoniazid, respectively, imbedded in L-leucine. Antibiotics were developed into inhalable antibiotic formulations for their utility in both first line and second line antibiotic treatment regimens. Capreomycin and kanamycin are typically administered by injection making them desirable candidates for the development of a needle-free delivery system that addresses the Grand Challenges in Global Health Initiative #3. In response to this challenge, unit-dose packaging that preserves powder properties by protecting them from moisture, oxidants, and UV exposure, and a low cost “active” dry powder inhaler, the PuffHaler, were developed and used as a prototype device, in addition to the Aerolizer, to disperse the microparticle antibiotic formulations. Antibiotic formulations show yields above 50% in small-scale powder production by CAN-BD. Capreomycin and kanamycin show improved powder yields in scale up experiments. The particle properties were characterized using scanning electron microscopy, Karl Fischer moisture analysis, Anderson Cascade Impaction studies, and X-ray diffraction. The inhalable antibiotic formulations are within a respirable size range (1–5 μm), and have less than 3% residual moisture. Unit-dose dry powder antibiotics have the potential to provide easy-to-use, stable products with improved safety profiles.