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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
Radiopharmaceuticals are administrated mostly via intravenous injection. To avoid damage to the blood vessels it is important to use a neutral pH solution. A range between 4-8 is acceptable. Due to the radioactive content, a minimal exposure time and quantity are preferred for the quality control employee. Therefore, pH paper is used where only a drop (< 10 µL) of product can determine the pH with an error of approximately ± 0.5 (Figure 6.7).
Methods of Protein Iodination
Published in Erwin Regoeczi, Iodine-Labeled Plasma Proteins, 2019
Lactoperoxidase is stable in solutions of low ionic strength up to 60°C from pH 3 to 10, and it is not denatured by 8 M urea.59 However, others67 reported progressive deactivation of the enzyme on storage at pH 3.0. Therefore, keeping it close to neutral pH appears to be safer. Bolton33 stores lactoperoxidase frozen.
Immunity
Published in David Sturgeon, Introduction to Anatomy and Physiology for Healthcare Students, 2018
The body’s first line of defence is provided by the skin and the mucous membranes that line the digestive, reproductive, respiratory and urinary tracts. The skin is the largest organ of the body and provides both a physical and chemical barrier. The epithelial cells that cover the skin’s surface are coated in a tough, protein-based substance called keratin that provides a water-resistant barrier known as the stratum corneum. These cells are constantly shed (desquamated) and replaced by new cells, which helps to prevent bacterial colonisation of the skin. Sebum, secreted onto hair follicles and the surface of the skin, also helps to inhibit fungal and bacterial growth and, when mixed with eccrine sweat, forms a fine acidic film called the acid mantle. It is a common misconception that the pH of the skin is neutral (pH 7) when it is actually quite variable and can range from between pH 4.5 and 6. This is one of the reasons why excessive washing with detergents can encourage opportunistic bacterial and yeast colonisation rather than inhibit it (particularly in sensitive areas). Eccrine sweat also contains an enzyme called lysozyme (splitting + enzyme) that helps to destroy the cell walls of some bacteria. Other secretions, such as tears, saliva and mucus, also contain this bactericidal enzyme. The next time you see a child (possibly your own) crying, with saliva dribbling from their open mouth and a great big snot bubble inflated from one nostril, marvel at the ‘sophistication’ of natural immunity as you wipe the anti-bacterial ‘paste’ from their angelic little face.
Chemotherapy-Induced Oral Complications and Prophylaxis Strategies
Published in Cancer Investigation, 2023
Aleksandra Śledzińska, Paulina Śledzińska, Marek Bebyn, Oskar Komisarek
Diet is a vital feature of dental health. Maintaining hydration involves drinking water and sugar-free liquids regularly. We encourage patients to avoid drinking very acidic beverages, especially between meals, because a continuous decrease in intraoral pH may be harmful to dental enamel (176). The most acidic ones are energy drinks, regular and diet sodas, juices, and sports drinks (177). Maintaining a stable neutral pH in the oral cavity is essential since this serves to prevent tooth demineralization (178). Patients should avoid “sticky” processed foods (caramels, taffy, etc.) that are rich in sugar that is difficult to remove (130,179). If patients consume a sugary beverage, they should do it in one sitting (over several minutes) rather than sipping it throughout the day. Such an approach aims to prevent repeated exposure of the teeth to sugar and decrease dental pH with each exposure. Moreover, it is advised to use a straw and avoid atypical drinking behaviors such as sipping, swishing, or holding acidic beverages in the vestibule (180).
Directly compressible formulation of immediate release rosuvastatin calcium tablets stabilized with tribasic calcium phosphate
Published in Pharmaceutical Development and Technology, 2022
Daniel Zakowiecki, Tobias Hess, Krzysztof Cal, Barbara Mikolaszek, Grzegorz Garbacz, Dorota Haznar-Garbacz
On the other hand, properly selected excipients can protect drug substances from adverse environmental factors and enhance the stability of finished dosage forms during storage. The ways of such chemical stabilization can be different and depend on the nature of the drug substance itself. For example, oxidation of lovastatin can be inhibited by employing antioxidants such as butylated hydroxyanisole (BHA) or alpha-tocopherol. Incorporation of titanium dioxide in film coatings can stabilize nifedipine included in tablet cores (Kaufman 1990; Béchard et al. 1992; Yoshioka and Stella 2002). Regulation of the microenvironmental pH of a solid dosage form can significantly impact both chemical stability of a drug and its dissolution behavior. It has been reported that the use of acidic agents in a tablet formulation improved stability of acetylsalicylic acid. Stability and solubility of an acid-labile drug, clarithromycin, were enhanced by addition of alkalinizing agents such as magnesium oxide or dibasic sodium phosphate (Delonca et al. 1975; Badawy and Hussain 2007; Park et al. 2015). Aforementioned amlodipine besylate is a highly hygroscopic drug, which absorbs moisture leading to its degradation. The degradation is pH dependent, faster in acidic and basic conditions. Various strategies to improve chemical stability of this drug were reported. Application of an anhydrous, non-hygroscopic substances having neutral pH, such as some grades of anhydrous dibasic calcium phosphate, seems to be advantageous (Lemmens et al. 2006; Singh et al. 2006).
Activation of peroxymonosulfate into amoxicillin degradation using cobalt ferrite nanoparticles anchored on graphene (CoFe2O4@Gr)
Published in Toxin Reviews, 2021
Elham Babaei Lashkaryani, Babak Kakavandi, Roshanak Rezaei Kalantary, Ahmad Jonidi Jafari, Mitra Gholami
The comparison between some transition metals (Co, Fe, Cu and Mn) shows that Co has the highest ability for efficient activation of PMS, as demonstrated in the literature (Li et al.2016a). Moreover, another advantage of Co ions would be the high performance in a wide spectrum of pH, especially neutral pH which is applicable for treatment of pharmaceutical and hospital wastewaters effectively (Qi et al.2014). However, the main problem of using Co ions in form of homogenous for environmental objectives is recovery of catalyst from aqueous solution as well as low surface/volume ratio because of strong tendency toward agglomeration. One of the solution is magnetization of Co ions by coupling with magnetic nanoparticles and production of CoFe2O4 (Pan et al.2017). Deng et al. (2017) synthesized a mesoporous CoFeO4/OMC composite for PMS activation to remove rhodamine B from aqueous solution and their findings revealed high efficiency of applied catalyst for activation of PMS and decolorization during 60 min (Deng et al.2017). The study of Xu et al. (2015) on dimethyl phthalate removal also showed the high efficiency of graphene–Co catalyst as a PMS activator (Xu et al.2015).