The objective of this study was to understand the behavior of particulate systems under different conditions of shear dynamics before and after granulation and to investigate the efficiency of powder lubrication. Three drug powders, metronidazole, colloidal bismuth citrate, and tetracycline hydrochloride, were chosen as model drugs representing noncohesive and cohesive powder systems. Each powder was individually granulated with microcrystalline cellulose and 5%PVP as a binder. One portion from each granulation was lubricated with different levels of magnesium stearate for 5 minutes. The powder characterization was performed on the plain powders, nonlubricated and lubricated granules using powder rheometer equipped with a helical blade rotating and moving under experimentally fixed set of parameters. The profiles of interaction during the force-distance measurements indicate that powder compresses, expands, and shears many times in a test cycle. Test profiles also clearly reveal existence of significant differences between cohesive and noncohesive powders. In all cases lubrication normalized the overall interactive nature of the powder by reducing peaks and valleys as observed from the profiles and reduced the frictional effect. The developed methods are easy to perform and will allow formulation scientists to better understand powder behavior and help in predicting potential impact of processing factors on particulate systems.
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http://dx.doi.org/10.1208/pt060349 | DOI Listing |
Environ Pollut
December 2024
Biomedical Engineering Institute, Chiang Mai University, Chiang Mai 50200, Thailand; Biomedical Engineering and Innovation Research Center, Chiang Mai University, Chiang Mai, 50200 Thailand. Electronic address:
Exposure to ambient air pollution is associated with several noncommunicable diseases, and it adversely affects the respiratory system and other organ systems. Several studies have investigated the underlying mechanisms of biological response to air pollutants using conventional techniques, but there is a lack of research on the effects of air pollution at the cellular level. This study developed a dual system that combines PM (particulate matter <2.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address:
The evolution of precursors to form secondary organic aerosol (SOA) is still a challenge in atmospheric chemistry. Chamber experiments were conducted to simulate the ambient OH oxidation of naphthalene and α-pinene, which are typical markers of anthropogenic and biogenic emissions. Particulate matters were sampled by quartz filters and were analyzed by comprehensive two-dimensional gas chromatography (GC×GC) coupled with a thermal desorption system (TD) and a mass spectrometer (MS).
View Article and Find Full Text PDFSci Rep
December 2024
Department of Civil Engineering, Sharif University of Technology, Tehran, Iran.
Air pollution, a global health hazard, significantly impacts mortality, cardiovascular health, mental well-being, and overall human health. This study aimed to investigate the impact of air pollution and meteorological factors on cardiovascular mortality rates in Mashhad City, northeastern Iran in 2017-2020. We utilized a Random Forest (RF) model in this study.
View Article and Find Full Text PDFSci Rep
December 2024
Clean Energy Technologies Research Institute (CETRI), Process Systems Engineering, Faculty of Engineering & Applied Science, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada.
Real-world emissions of particulate matter (PM) and smoke opacity were studied for an older-model diesel pickup truck during four types of driving tests, namely fixed-point test, snap-acceleration test, road test, and hill road test (uphill/downhill). A portable emissions measurement system (PEMS) and an opacimeter were used to measure real-time concentrations of PM and smoke opacity, respectively, and simultaneously. Correlation analysis showed a significant positive association between PM and opacity, suggesting the feasibility of using an opacimeter to estimate PM mass emissions from diesel vehicles.
View Article and Find Full Text PDFSci Rep
December 2024
Civil and Environmental Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.
Air pollution monitoring and modeling are the most important focus of climate and environment decision-making organizations. The development of new methods for air quality prediction is one of the best strategies for understanding weather contamination. In this research, different air quality parameters were forecasted, including Carbon Monoxide (CO), Nitrogen Monoxide (NO), Nitrogen Dioxide (NO), Ozone (O), Sulphur Dioxide (SO), Fine Particles Matter (PM), Coarse Particles Matter (PM), and Ammonia (NH).
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