These measurements were used to obtain an initial linear rate of DNA-Methyl Green degradation, which correlates directly to DNase activity. 2.4. In Vitro Characterization of Particle Size Aerodynamic particle sizing of all PRINT aerosols was performed using the aerodynamic particle sizer (APS) spectrometer (Model no. 3321, TSI Inc. Shoreview, MN, USA). Dry powder aerosols were dispensed into an aerosol generator using an insufflator device and a volume-calibrated hand pump (Penn Century Inc.,

PA, USA). Next-generation impactor (NGI) experiments were used to compare the aerodynamic size distribution of PRINT zanamivir formulations Inhibitors,research,lifescience,medical to Relenza. Before Selleck ACY-1215 testing, NGI stages were coated with silicone oil. To test PRINT formulations, 5mg of PRINT-zanamivir particles were loaded into a size 3 HPMC capsule, which was loaded into a Monodose device (Plastiape SpA). The loaded Inhibitors,research,lifescience,medical Monodose device was attached to an NGI (MSP Model 170) and tested using a 60L/min flow rate for 4seconds. Deposited drug was rinsed from the capsule, the device, device adapter, induction port, filter, and each stage of the NGI using 5 to 25mL HPLC grade water, and the zanamivir content in each rinsate was measured using HPLC and compared to standard curves

to determine the absolute weight of zanamivir in the capsule, device, and impactor. Similar methodology was used to measure the aerodynamic particle Inhibitors,research,lifescience,medical size distribution of Relenza, with the exception that preseparator stages were used to determine the deposited dose of large (>10μm) zanamivir/lactose agglomerates. Laser diffraction was used to determine the geometric

size of micronized itraconazole crystals. Inhibitors,research,lifescience,medical Specifically, measurements were performed using a Sympatec HELOS instrument, operated at 5 bar primary pressure and 105mbar secondary pressure. 2.5. Gamma Scintigraphy In Vivo Canine Lung Deposition Imaging Torus aerosols (1.5μm and 6μm) for the in vivo canine deposition study were fabricated out of a lactose-albumin-leucine Inhibitors,research,lifescience,medical blend (64/32/4 mass ratio) and were further labeled with technitium-99 (Tc99m) by isopropyl alcohol coevaporation. Naïve (unlabeled) PRINT particles were mixed with very Tc99m in isopropyl alcohol. Ratios of Tc99m:PRINT particle:IPA were held at 50mCi:50mg:0.75mL. The mixture was the gently shaken to mix without coating the material on sides of the vials. The mixture was then evaporated under a gentle stream of N2. The labeled particles were then immediately loaded into insufflators and used for either validation studies or canine exposures. In order to confirm the radiolabeling process, the mass median aerodynamic diameter (MMAD) of the materials before and after labeling and the activity median aerodynamic diameter (AMAD) were determined with a next-generation impactor (NGI). The NGI was operated at 30L/min for all testing.