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Methods and Equipment for Quality Control of Radiopharmaceuticals
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Rolf Zijlma, Danique Giesen, Yvette Kruiter, Philip H. Elsinga, Gert Luurtsema
The measurement principle is built on the colligative property of freezing-point depression (Figure 6.10). For example, the freezing point of the solution will decrease upon adding a solution to a liquid. The depression is 1.858 K per 1 mole of ideally solved compound in one litre of water. This effect depends solely on the number of particles in the liquid and not on the physical or chemical properties of the solutes. Due to this linear correlation, the osmolality of a sample can be determined by precisely measuring its freezing point.
Glycerine in Oral Care Products
Published in Eric Jungermann, Norman O.V. Sonntag, Glycerine, 2018
The value of aw is a colligative property. A 30% solution of glycerine generally will not support microbiological growth. A 40% solution of sorbitol is necessary to achieve that effect [3].
Circulation of fluid between plasma, interstitium and lymph
Published in Neil Herring, David J. Paterson, Levick's Introduction to Cardiovascular Physiology, 2018
Neil Herring, David J. Paterson
Osmotic pressure is a ‘colligative’ property, like freezing point depression; that is, it depends primarily on solute concentration, not chemical identity. The osmotic pressure (n) of an ideal solution is described by van’t Hoff’s law, namely
Effect of different molecular weight PLGA on flurbiprofen nanoparticles: formulation, characterization, cytotoxicity, and in vivo anti-inflammatory effect by using HET-CAM assay
Published in Drug Development and Industrial Pharmacy, 2020
A. Alper Öztürk, Evrim Yenilmez, Behiye Şenel, Hülya Tuba Kıyan, Umay Merve Güven
Among the various polymeric carriers used for drug delivery purposes, PLGA has a very important place in applications combining targeting, imaging, diagnosis, and therapy. Furthermore, this polymer can be readily hydrolyzed to monomers as lactic acid or glycolic acid and then excreted from the body by normal metabolic pathways [16]. When Blank and FLB-loaded NP formulations were evaluated, no statistically significant difference was observed between blank formulations and FLB-loaded formulations (p > 0.05). However, in the literature, polymer degradation leads to the formation of smaller polymer fragments of low Mw, resulting in an increase in the number of molecules in the medium. Because osmotic pressure is a colligative property and depends on the total number of molecules, smaller molecules resulting from polymer degradation increase the osmolality of the solution [44]. Increased osmolality has been reported to induce free radical production and activate apoptotic cell death mechanisms [45,46]. In a study, researchers showed that there was a linear correlation between the disintegration of polymeric structure and observed osmolality and cell death by regression analysis [47]. Therefore, the higher Mw formulation A3 is thought to exhibit relatively higher cytotoxicity than others. According to cytotoxicity studies of Resomer® RG 502 H, Resomer® RG 503 H, and Resomer® RG 504 H in the literature; the cell viability values are also different due to using of different cells, cytotoxicity evaluation times, polymer amounts, excipients, and preparation steps. For example, prepared a NP with Resomer® RG 502 H polymer in a study, and A549 cells showed cell viability of more than 90% in 50 µM after 24 h, whereas other studies showed that cell viability of less than 70% after 80 µg.mL−1 in their polymeric NPs with Resomer® RG 502 H and Resomer® RG 503 H [48,49]. In another study, the researcher used Resomer® RG 502 H and Resomer® RG 503 H for NP formulation and found cell viability of over 90% at 500 µg.mL−1 at the end of 48 h on breast cancer cells [50]. In a different study using Resomer® RG 502 H and Resomer® RG 504 H, over 90% cell viability was observed at 360 µg.mL−1 after 24 and 48 h incubation time [23].