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Advances in Process Controls and End-Point Determination
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Kevin A. Macias, M. Teresa Carvajal
With the entire process complete, and desired physical attributes confirmed, the final granulation is often tested for chemical homogeneity. Assessment of chemical composition can be evaluated by fractionating the granulation by sieve analysis and measuring the chemical composition within each size fraction. Analysis of sieve fractions is possible by direct testing using wet chemistry or by indirect spectroscopic means and is used to contextualize the risk to blend uniformity should any segregation occur during processing.
The Properties and Applications of Nanodiamonds
Published in Lajos P. Balogh, Nano-Enabled Medical Applications, 2020
Vadym Mochalin, Olga Shenderova, Dean Ho, Yury Gogotsi
Compared with gas treatment (at 400–850◦C), wet chemistry requires milder conditions and provides a better selectivity through a large number of functional group conversions known in organic chemistry (Fig. 11.5). Reactive C–F and C–Cl surface species created by halogen annealing and photochemical chlorination have also been used in numerous wet chemical reactions [67, 68].
Conclusion
Published in Nate F. Cardarelli, Tin as a Vital Nutrient:, 2019
Several chapters (22 and 23) were added at this point in the text. The abstract of the presentation by Dr. Brinckman at the Tin and Cell Malignancy Symposium was all that was available to us. In order to meet certain time constraints we felt it better go ahead and notify the reader, even if in abbreviated form, that elaborate methods are being developed at the National Bureau of Standards for the speciation of tin compounds in cellular media at ultra low concentrations, i.e., below a part per million. The analytical aspects of organotin chemistry have long been bedeviled by lack of sufficient sensitivity at low concentrations as well as the chemical characterization of what has been detected. Methodology developed over the last 40 years has been keyed to wet chemistry methods that are not applicable at low and ultralow concentration, or instrumental means where volatile compositions are lost. All spectrographic-type analyses must be suspect and the reputed data should be assumed, if not accurate, to err on the low side. Modern tools such as high-performance liquid chromatography coupled with atomic absorption,58119mSn Mossbauer spectroscopy,60,61 X-ray crystallography,62 pulsed Fourier transform nuclear magnetic resonance coupled with polarography and other instrumental methods are indeed promising.
Magnetic nanoparticles: multifunctional tool for cancer therapy
Published in Expert Opinion on Drug Delivery, 2023
Sumera Khizar, Eslam Elkalla, Nadia Zine, Nicole Jaffrezic-Renault, Abdelhamid Errachid, Abdelhamid Elaissari
Various shapes have been synthesized to improve magnetization by reducing surface anisotropy and increasing exchange anisotropy [9]. Different methodologies are available for fabricating MNPs in various forms such as nanowires, nanorods, and nanocubes. These techniques include wet chemistry or ‘bottom-up’ methods, namely solvothermal, hydrothermal, co-precipitation, sol-gel, electrochemical, flow injection synthesis, and laser pyrolysis procedures [10]. In the last era, the core/shell morphology of MNPs containing a core of iron has been extensively used from the perspective of the magnetic influence and loading/release of particular drugs [11]. MNPs attain controllable and precise drug release by bonding drug moieties through linkers with the ability to be cleaved or to shell the polymer, enclosing them with the capability to release drugs [12].
Development of chlorine-induced lung injury in the anesthetized, spontaneously breathing pig
Published in Toxicology Mechanisms and Methods, 2021
Rachel Watkins, Rosi Perrott, Simon Bate, Philippa Auton, Sarah Watts, Alexander Stoll, Stephen Rutter, Bronwen Jugg
The pig has been used widely to investigate mechanisms of lung injury caused by inhalation of a range of toxic chemicals as well as therapeutic strategies to ameliorate the injury: phosgene (Brown et al. 2002; Smith et al. 2009; Grainge and Rice 2010; Graham et al. 2018; Rendell et al. 2018), sulfur mustard (Fairhall et al. 2010; Jugg et al. 2013, 2016) and chlorine (Gunnarsson et al. 1998; Wang et al. 2002, 2004, 2005). Historically, studies exposing pigs to chlorine have used mechanically ventilated pigs with the gas delivered from the cylinder or reservoir directly to the lungs via the ventilator; the animals had neuromuscular blockade during exposure (Wang et al. 2002; Wang et al. 2004; Wang et al. 2005). Assessment of chlorine dose has been inferred from chlorine passed through a bubbler and pH changes or other wet chemistry techniques (Gunnarsson et al. 1998). Measurement of real-time chlorine concentration is preferred to post-exposure analysis as it allows for accurate dose delivery by targeting the inhaled dose (ID). This is achieved by adjusting the real-time inhaled gas concentration in response to changes in the animals’ minute volume, with the aim of reducing inter-individual variability. This approach has resulted in delivery of highly accurate inhaled doses of phosgene (Graham et al. 2018; Rendell et al. 2018) and sulfur mustard (Fairhall et al. 2008) in established pig models.
Morbidity and mortality resulting from acute inhalation exposures to hydrogen fluoride and carbonyl fluoride in rats
Published in Inhalation Toxicology, 2018
Adolph J. Januszkiewicz, Matthew A. Bazar, Lee C. B. Crouse, Michael A. Chapman, Steven E. Hodges, Steven J. McCormick, Arthur J. O’Neill
Earlier studies used wet chemistry analyses, sometimes with the use of an ion-specific electrode. These techniques may underestimate fluoride levels if the volume or the alkalinity of the collection media is insufficient, particularly when high fluoride concentrations are measured and fluoride is ineffectively captured. Adsorption or reaction of the gases with gas sampling materials could also lead to an underestimation of actual exposure concentrations. Haskell Laboratory realized these experimental issues in the early 1990’s (Valentine, 1990; Valentine & Makovec, 1993). Finally, wet chemistry techniques are limited insofar that only intermittent time-weighted average concentrations can be achieved, with the possibility of missing fluctuations in the actual exposure concentrations. The use of the FTIR, non-reactive/adsorptive materials, and in-line measurements help to avoid these uncertainties in exposure conditions while producing a more dynamic profile of the exposure concentration.