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Nanoparticle Synthesis and Administration Routes for Antiviral Uses
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
João Augusto Oshiro-Júnior, Kammila Martins Nicolau Costa, Isadora Frigieri, Bruna Galdorfini Chiari-Andréo
Dynamic light scattering is a technique that aims to determine the diffusion coefficients of macromolecules in solution, allowing to obtain information such as aggregation and the average size of the particles. This information is obtained in a simpler and easier way than using microscopy techniques; however, the results are less accurate (Fischer and Schmidt 2016; Stetefeld et al. 2016; Malm and Corbett 2019; Nepomnyashchaya 2019).
Drug Substance and Excipient Characterization
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Parind M. Desai, Lai Wah Chan, Paul Wan Sia Heng
In recent years, light scattering and light obscuration techniques have gained popularity as methods for determining particle size down to about 1 µm using Mie theory or Fraunhofer theory. The measurement of submicron particles had been difficult until the introduction of photon correlation spectroscopy for particle sizing. This latter technique enables particles from nanometers to a few microns to be measured.
Rapid Methods in Cosmetic Microbiology
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Optical spectroscopy is an analytical tool that measures the interactions between light and the material being studied. Light scattering is a phenomenon in which the propagation of light is disturbed by its interaction with particles. For example, “Mie scattering” is one form of light scattering in which scattered light is proportional to the particle size. Therefore, many particle counters employ Mie scattering to detect, count and size particles in an environment, such as those used in cleanrooms and other microbiologically controlled areas.
Encapsulation of propolis extracts in aqueous formulations by using nanovesicles of lipid and poly(styrene-alt-maleic acid)
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Chatmani Buachi, Charothar Thammachai, Brian J. Tighe, Paul D. Topham, Robert Molloy, Patchara Punyamoonwongsa
The light scattering (or turbidity) caused by particles is generally related to the particle size. The greater turbidity the formulation display (or the increased light absorption), the larger particle sizes the system would contain. This concept can be applied for the investigation of the particle aggregation during the shelf-life storage. As noticed, the samples at the mass ratios of 90:10 and 80:20 (PSMA/PC), based on DLPC (Figure 5) or DMPC (Figure 6), exhibit an excellent optical transparency with the least UV light absorption (Abs < 0.05), implying the formation of the most stable nano-scaled mixed assemblies that do not scatter the light source. After 432 h, these formulations show the negligible change in their Abs values. Other formulations show a noticeable increasing in the Abs value, suggesting the presence of particle aggregation.
Biopredictive tools for the development of injectable drug products
Published in Expert Opinion on Drug Delivery, 2022
Mônica Villa Nova, Kennard Gan, Matthias G. Wacker
First, injectable dosage forms often comprise the drug in the dissolved and the solid-state. The separation of particles in the micrometer or nanometer range requires the selectivity of the assay for the size fraction of interest to be evaluated [61,117]. This can be achieved by measuring particle retention using suitable standards, such as dextran or gold nanoparticles [61]. In this context, light scattering methods may not be sensitive enough to reliably detect and quantify the low particle concentrations remaining in the sample [118]. Hence, chemical detection methods together with a sufficiently stable particle standard are preferred. Best practices involve a combination of both, quantification of the physical form (e.g., by using light scattering methods) and a mass balance study using chemical quantification methods [61,118].
Advances in endoscopy for colorectal polyp detection and classification
Published in Baylor University Medical Center Proceedings, 2020
Vijeta Pamudurthy, Nayna Lodhia, Vani J. A. Konda
Spectroscopy quantitatively characterizes objects based on their interaction with light in real time. Light scattering can be elastic or nonelastic. The most common type of nonelastic spectroscopy is Raman spectroscopy, which measures vibrational and rotational aspects of molecules and provides insight into the molecular and biochemical composition of the tissues. Raman spectroscopy has shown promising results in detecting adenomatous and cancerous tissues, differentiating normal and precancerous tissues, detecting precancerous and cancerous lesions early, and identifying flat lesions.46 In a study assessing the potential of Raman spectroscopy for discriminating between normal tissue and cancerous tissue, two regression methods were used on selected parameters to determine a diagnostic accuracy of 88% and 83% in discriminating between normal and cancerous tissues.47