Glycerine in Bar Soaps
Eric Jungermann, Norman O.V. Sonntag in Glycerine, 2018
Since the semiboiled and cold processes do not allow for washing impurities out of the soap, very pure raw materials must be used. The quality of raw materials is important with transparent soaps because of color and clarity considerations. Transparent soaps contain additives that interfere with the formation of large crystals. Alcohol, sugar, glycerine, sorbitol, castor oil, and other materials with hydroxyl groups are recommended for retarding crystal growth. Choosing fats that are less saturated or have extra hydroxyl groups, such as castor oil, also aid transparency. However, unsaturated fats make soap softer and stickier and decrease its lather, so they must be combined with saturated fats which are less favorable to transparency. The alkali used usually is sodium hydroxide, although potassium hydroxide and triethanolamine are also used, and tend to give better transparency.
The Study of Drug Metabolism Using Radiotracers
Graham Lappin, Simon Temple in Radiotracers in Drug Development, 2006
On occasions it is necessary to collect exhaled volatiles. If radioactivity is exhaled as 14CO2, then this can be trapped either by a solution of sodium hydroxide or in a mixture of 2-ethoxyethanol:ethanolamine (3:1 v/v). Although some laboratories use potassium hydroxide, others avoid it, as potassium exhibits a relatively high radioactive background. In small animal studies, particularly with the laboratory rat, metabolism cages can be designed for the total collection of exhaled air. A schematic showing a CO2 collection system is shown in Figure 3.4. The inlet to the cage is fitted with a device to absorb CO2, so as not to saturate the traps with atmospheric CO2. On the outlet of the cage there are two traps arranged in series. The first trap will efficiently retain 14CO2, and therefore the second trap should be devoid of radioactivity. If the first trap becomes saturated with exhaled CO2, then radioactivity will appear in the second trap. If radioactivity is found in the second trap in any appreciable quantity, then there is a chance that the whole trapping system became saturated and some 14CO2 was lost to the atmosphere. The total volume of each trap is recorded, and from the analysis of aliquots of known volume, the total radioactivity present in the traps can be calculated.
Prevention of Microbial Contamination during Manufacturing
Philip A. Geis in Cosmetic Microbiology, 2020
Alkaline cleansers such as sodium hydroxide, ammonium hydroxide, potassium hydroxide or borax solutions are used as an alkaline wash to remove soils such as oils, fats, grease particulates and films (68). The alkalinity of sodium hydroxide solutions may enhance the solubility of organic process residues and in some cases facilitate hydrolysis, but it can also facilitate the precipitation of salts or oxides of such ions as calcium, magnesium and iron if these ions are present during the cleaning process.
Design, synthesis, and biological screening of a series of 4′-fluoro-benzotriazole-acrylonitrile derivatives as microtubule-destabilising agents (MDAs)
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Federico Riu, Roberta Ibba, Stefano Zoroddu, Simona Sestito, Michele Lai, Sandra Piras, Luca Sanna, Valentina Bordoni, Luigi Bagella, Antonio Carta
Scheme 1 depicts the synthetic route for the designed compounds 5–13. The benzotriazole derivative 1 was obtained as previously reported.41 Compound 1 was used as a starting material to obtain three geometric isomers (2–4) bearing an acetonitrile chain on each of the three nitrogen atoms on the triazole ring. The reaction was conducted under basic conditions, by potassium hydroxide (KOH). Acetonitrile intermediates 2–4 were fully characterised, N-1 isomer (compound 2) was identified through NOESY NMR spectra, while isomers N-2 and N-3 were identified by chemical shift of the CH2 carbon at 13 C NMR spectra, see Figures S8 and S10 in the Supplemental Material. The stereochemistry of the double bond was identified as Z through 1H- and 13 C NMR spectra, as already established and described.30 The chemical shift of the 1H and 13 C for the CH moiety clearly distinguish if the Z or E isomer is obtained.
Strategies to improve the diagnosis and clinical treatment of dermatophyte infections
Published in Expert Review of Anti-infective Therapy, 2023
Although microscopic examination is performed to diagnose dermatophyte infections, potassium hydroxide (KOH) is used to dissolve keratinaceous materials. The sensitivity of this simple and inexpensive diagnostic method, which has been in use for more than a century, is between 87% and 91%. Clinical samples for direct microscopic examination can be obtained easily as follows. The area with suspected fungal infection is first cleaned with a 70% alcohol swab to remove artifacts. Alcohol swabs are preferred, as the use of cotton during this cleaning process may induce artifacts. Multiple affected areas are scraped with a blunt scalpel (No. 15), and the sample obtained is carefully transferred to a slide. The active border of erythematous annular lesions is sampled from the roof of the vesicles or pustules. In patients with tinea capitis, hair is pulled using forceps or tweezers. Overall, this simple technique can often reveals further information; for example, in tinea capitis, the size and array of spores can provide clues to the genus of the dermatophyte that is present and, in unstained mounts, the presence or absence of pigmentation in hyphae is a helpful hint.
Lactobacillus casei reduces the extracellular matrix components of fluconazole-susceptible Candida albicans biofilms
Published in Biofouling, 2021
Beatriz H. D. Panariello, Marlise Inez Klein, Luana Mendonça Dias, Amanda Bellini, Vitoria Bonan Costa, Paula Aboud Barbugli, Ana Claudia Pavarina
The biofilms were stained with LIVE/DEAD BacLight viability kit (Molecular Probes; Invitrogen, Eugene, OR, USA) and with CalcoFluor White stain (Sigma-Aldrich, St Louis, MO, USA) combined with Sypro Ruby (Sigma-Aldrich, St Louis, MO, USA). First, a stock solution of 0.1 M potassium hydroxide (KOH; 1 mmHg; pH ∼13.5) (Sigma-Aldrich, St Louis, MO, USA) was prepared and kept at room temperature until its use. After biofilm maturation for 48 h, 20 µl of KOH solution and 20 µl of CalcoFluor White stain were added to the wells containing biofilms to bind cellulose and chitin in the cell wall of C. albicans (Hageage and Harrington 2003; Rasconi et al. 2009). The plate was wrapped with aluminum foil and incubated for 10 min. Later, the biofilms were washed twice with 500 µl of phosphate-buffered saline (PBS; 57 mM NaH2PO4, 50 mM Na2HPO4, 200 mM NaCl; pH 7.33) and 250 µl of Sypro Ruby (following the manufacturer's instructions) were added to detect proteins in the ECM (Alvarez-Castelao et al. 2019). The plates were incubated again for 20 min, the dyes were removed from all the wells, the biofilms were washed once with 500 µl of PBS and resuspended with 500 µl of fresh PBS.
Related Knowledge Centers
- Acid
- Crystallization
- Hydroxide
- Inorganic Compound
- Lye
- Potassium
- Solvation
- Sodium Hydroxide
- Soap
- Thermal Stability