The production of monodisperse human albumin millimicrospheres (diameter less than 1 micron) and labeling with 99mTc is described. A system constructed to nebulize and deliver a dry aerosol yielded a lung delivery efficiency of approximately 25%. In 48 patients without and with varying degrees of chronic obstructive lung disease, quantitative comparison with 81mKr (penetration index, regional distribution of activity in the lungs) demonstrated similar penetration of the particles to the lung periphery (r = 0.89 and r = 0.94, respectively). Qualitative comparison with 81mKr or 127Xe showed complete or a high degree of diagnostic agreement in all but one patient. Semiquantitative scoring of hot spots as a substrate of local turbulent airflow showed a close inverse correlation (r = -0.82) with the forced expiratory volume in 1 s (FEV 1.0%), thus providing additional information about the severity of the airway obstruction. In 24 patients with suspected pulmonary embolism, complete agreement between aerosol and 81mKr images was found in all patients studied. For same-day ventilation/perfusion studies, labeling of the millimicrospheres with 111In yielded images of comparable quality to those obtained with the 99mTc-labeled aerosol.
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http://dx.doi.org/10.1007/BF00256581 | DOI Listing |
Pharmaceutics
January 2025
Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, USA.
Dry powder inhalers (DPI's) are becoming increasingly popular due to growing interest in pulmonary drug delivery and their performance is the net result of a series of processes carried out during the formulation development and manufacturing process such as excipient selection, blending, milling, filling, and spray drying. To reach the small airways of the deep lung, the active pharmaceutical ingredients (API) particles need to have an aerodynamic diameter of 1-5 μm to avoid impaction and particle sedimentation in the upper respiratory tract, and due to this small particle size, the powder becomes highly cohesive resulting in poor flow. Therefore, API is usually blended with a coarse carrier to improve flowability, and due to its large size, it is more fluidizable than the micronized drug.
View Article and Find Full Text PDFToxics
December 2024
Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), Nikolai-Fuchs-Str. 1, 30625 Hannover, Germany.
Zinc sulphide is a widely used inorganic powder, and its production has reached quantities greater than 1000 t/year. Therefore, in accordance with OECD guideline 436, an acute inhalation test was implemented to provide more accurate data. This study is crucial for ensuring the safety of workers exposed to zinc sulphide dust and complying with regulatory requirements for REACH.
View Article and Find Full Text PDFFront Microbiol
January 2025
Diagnostic and Research Institute for Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria.
The application of antimicrobial surfaces requires proof of their effectivity by methods in laboratories. One of the most common test methods is ISO 22196:2011, which represents a simple and inexpensive protocol by applying the bacterial suspension with known volume and concentration covered under a polyethylene film on the surfaces. The incubation is then conducted under defined humidity conditions for 24 h.
View Article and Find Full Text PDFJ Drug Deliv Sci Technol
February 2025
Department of Chemical Engineering, University of Rhode Island, Kingston, RI 02881 USA.
Macrophages are an integral part of the innate immune system and act as a first line of defense to pathogens; however, macrophages can be reservoirs for pathogens to hide and replicate. Tuberculosis, influenza virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are common diseases whose pathogens are uptaken into macrophages. Current treatments for diseases such as these are limited by the therapeutic delivery method, which typically involves systemic delivery in large, frequent doses.
View Article and Find Full Text PDFJ Aerosol Sci
January 2025
Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, Richmond, VA.
The use of air-jet dry powder inhalers (DPIs) offers a number of advantages for the administration of pharmaceutical aerosols, including the ability to achieve highly efficient and potentially targeted aerosol delivery to the lungs of children using the oral or trans-nasal routes of administration. To better plan targeted lung delivery of pharmaceutical aerosols with these inhalers, more information is needed on the extrathoracic (ET) depositional loss in pediatric subjects when using relatively small (e.g.
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