Nutrition
Barbara Smith, Linda Field in Nursing Care, 2019
Glycerol consists of carbon, hydrogen and oxygen atoms. Fatty acids can be saturated or unsaturated, depending on the number of hydrogen atoms they contain. Saturated fatty acids are those in which all carbon atoms are filled to capacity (hence the term ‘saturated’) with hydrogen; an example is butyric acid found in butter. An unsaturated fatty acid can accommodate more hydrogen atoms than it currently does. It has at least two carbon atoms that are not attached to a hydrogen atom; instead, there is a double bond between the two carbon atoms. Fatty acids with one double bond are called monounsaturated fatty acids, and those with more than one double bond are called polyunsaturated fatty acids. Linoleic acid is an example of a polyunsaturated fatty acid found in vegetable oil.
Natural Products and Stem Cells and Their Commercial Aspects in Cosmetics
Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters in Cosmetic Formulation, 2019
Glycerin, also known as glycerol, is a viscous, sweet-tasting liquid that is the by-product of saponified animal fats and oils. It is believed that glycerin was discovered in 1779 by the Swedish chemist Carl Wilhelm Scheele (Corbeil et al., 2000). Glycerin derivatives are used in many industries, including in plastics or as nitroglycerin in explosives. Moreover, glycerin is now one of the primary ingredients in countless cosmetic products as a solvent and humectant. Glycerin is also considered an effective moisturizer due to its hygroscopic properties. However, large amounts of glycerin should be avoided in skin products since glycerin may be irritating. Nowadays, glycerin is often obtained as the by-product of biodiesel production and is not necessarily from animal sources (Fan et al., 2010). Researchers are also exploring conversion of glycerin to other chemicals that can be used in cosmetic products, including citric acid, lactic acid, 1,3-dihydroxyacetone (DHA), and 1,3-propanediol (Tan et al., 2013).
Handling, Safety, and Environmental Aspects
Eric Jungermann, Norman O.V. Sonntag in Glycerine, 2018
Use of copper in any of its alloyed forms should be avoided in tankage or lines and equipment. Brass or bronze valves are especially vulnerable sources of copper contamination. There are two major reasons for preventing copper contamination in glycerol. The first is that copper is a universal toxicant and a powerful prooxidant. Glycerol is a raw material for mono-, di-, and triglyceride production as well as a host of ester derivatives used in the food, cosmetic and pharmaceutical industries. Many producers of these products have stringent specifications for minimum copper content. Furthermore, glycerol in many of its uses, will be in contact with many organic materials in its final use form in cosmetics, pharmaceuticals and foods, where autoxidation is a primary concern. Thus, copper traces are detrimental both for toxicity and for prooxidant reasons. Second, copper traces are catalysts for the dehydration of glycerol to acrolein with heat. This is a toxic, lachrymatory material of relatively high hazardous nature (LD50 orally in rats is 26 mg/kg body weight [7]).
Ethylcellulose-stabilized fat-tissue phantom for quality assurance in clinical hyperthermia
Published in International Journal of Hyperthermia, 2023
Mattia De Lazzari, Anna Ström, Laura Farina, Nuno P. Silva, Sergio Curto, Hana Dobšíček Trefná
The use of the polymer ethylcellulose (EC) as a net-forming agent together with edible oils has been proven to have several applications, for instance, in the food [29] and pharmaceutical [30] fields. In the ethylcellulose oleogel-based fat phantom, we mixed canola oil with glycerol to achieve the appropriate dielectric properties. Canola oil, like most vegetable oils, has both low relative permittivity of about 4 and low conductivity of about 0.02 S/m in the 10 MHz to 1 GHz range [31–34]. Glycerol is a polyol compound that finds applications in the food and cosmetics industry due to its nontoxicity and bacteria resistance. As assessed by Meany et al. [35], pure glycerol has permittivity around εr = 40 for frequencies below 1 GHz. Above 1 GHz, its permittivity decreases and stabilizes around εr = 9. Its conductivity exhibits moderate values reaching σ = 0.5 S/m for frequencies below 1 GHz.
The place of a ketogenic diet in the treatment of resistant epilepsy: a comprehensive review
Published in Nutritional Neuroscience, 2023
Patients should be warned about hidden carbohydrate sources. Permitted excipients; aspartame, cellulose, gelatin, glycerol, paraffin, hypromellose, lactulose, sucralose, xanthan gum. Not recommended excipients; dextrin, fructose glucose, lactitol, lactose, maltodextrin, mannitol, sucrose, sorbitol, starch, xylitol [67]. Although glycerol is included in a class of permitted excipients, there is also a study that does not agree with it [68]. Although glycerol is a part of carbohydrate metabolism, it is also produced from fatty acids [69]. Given the physiological nature of glycerol production and its (usually) low contribution as an excipient in medicines, the amount of exogenous glycerol can be neglected. Therefore, it was judged acceptable for use in KD [67]. Finally, special care should be taken when prescribing liquid formulations labeled as sugar-free. It is possible that some sugar-free medicines contain excipients such as sorbitol sucrose, which are not recommended in KD [68].
A transfersomes hydrogel patch for cutaneous delivery of propranolol hydrochloride: formulation, in vitro, ex vivo and in vivo studies
Published in Journal of Liposome Research, 2023
Changzhao Jiang, Rui Ma, Xiumei Jiang, Renhua Fang, Jincui Ye
The prescription amount of glycerine (13.35%) was weighed into a beaker, supplemented with sodium polyacrylate (3.00%), aluminium glycinate (0.17%), EDTA-2Na (0.02%), propylene glycol (1.87%), myristate (2.34%) as well as menthol (2.34%) and fully stirred to obtain the glycerol phase. In addition, the prescribed amount of gelatine (0.62%) and PVP K90 (1.34%) were added into the beaker, followed by the addition of distilled water (74.78%) and stirring at 80 °C at 600 rpm for 30 min. The mixture was cooled and supplemented with tartaric acid (0.17%) to obtain an aqueous phase. The aqueous phase and the prepared transfersomes suspension were added to the glycerol phase and continuously stirred for 30 min at 300–400 rpm to obtain a uniform solution. Bubbles were removed by centrifugation at 6000 rpm at 25 °C for 10 min. Then, the definite weight of the above solution was coated on a backing layer, dried at 50 °C for 4 h, covered by a release liner and finally cut to a size of 5 cm2 using cutting machine. The patches were subjected to further analyses.
Related Knowledge Centers
- Antiviral Drug
- Chirality
- Glyceride
- Humectant
- Lipid
- Triol
- Antimicrobial
- Pharmaceutical Formulation
- Hydroxy Group
- Prochirality