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Humectants in Personal Care Formulation: A Practical Guide
Published in Randy Schueller, Perry Romanowski, Conditioning Agents for Hair and Skin, 2020
Inorganic humectants are typically the salts of inorganic acids. Calcium chloride is an example of this class. There is currently little use for this class of humectant in personal care formulation, because they have problems related to their corrosive effects and incompatibility with other raw materials (7). Additionally, since these materials are salts, their incorporation in personal care formulations, at amounts necessary to deliver substantial humectancy, can detract from the other desired properties of the formulation. For example, emulsion products such as creams and lotions have a tendency to destabilize due to the salting-out effect. The effect on surfactant-based cleansing products is well established; they cause the system to go beyond the peak of the salt curve, lowering viscosity and often depressing foam. These materials also tend to increase the potential for eye sting and irritation, and in powdered products, may desiccate the skin to an extent.
Hair Waving
Published in Dale H. Johnson, Hair and Hair Care, 2018
On the other hand, neutralizers are formulated at an acidic pH. This is largely due to the inherent instability of hydrogen peroxide at alkaline pH. For-mulating neutralizers at neutral to acidic pH is also helpful in removing any residual alkali that may be left in the hair due to incomplete rinsing of the waving lotion. Commercial neutralizers therefore contain some organic or inorganic acid such as citric or phosphoric.
Chemical Reactions of Glycerine
Published in Eric Jungermann, Norman O.V. Sonntag, Glycerine, 2018
Glycerine forms esters of many inorganic acids such as hydrogen halides, sulfuric, phosphoric, nitrous, nitric, and boric acids. Some of these are used as intermediates in chemical reactions, others have distinct end uses, such as tri-nitroglycerine, the well-known drug and explosive.
Novel therapies for glaucoma: a patent review (2013-2019)
Published in Expert Opinion on Therapeutic Patents, 2019
Paolo Guglielmi, Simone Carradori, Cristina Campestre, Giovanna Poce
In order to enhance water solubility, the same inventors developed urea-based FAAH inhibitors for the treatment of glaucoma [53]. The inventors synthesized and fully characterized 39 compounds and their formulations to further test them by an in vitro/ex vivo protocol in male NMRI mice to assess the inhibitory activity, the aqueous solubility and the metabolic stability against human liver microsomes in presence/absence of NADPH. These new derivatives showed promising solubility profiles (>14 mg/mL) suitable for ocular instillation but were largely metabolized by CYP enzymes. The FAAH inhibitory activity is reported in Table 4 at 0.1 mg/Kg, po. The compounds displayed the ability to modulate the activity of FAAH with relatively high peripheral activity (liver > brain) after oral administration in in vivo (mice) as reported for the previous ones and their general structure. The nature and type of the organic or inorganic acid for salt formation were important for the biological activity and the improved aqueous solubility. The R substituent (amide, urea, sulfonamide, sulfamate, or sulfamide) was preferred in the meta position with respect to the para, whereas the alkyl spacer followed the order: n = 1>2. The aryl could be substituted (especially in the meta position) with OCH3>OH>Hal or changed to a benzodioxol-5-yl ring.
Profiling the microbial contamination in aviation fuel from an airport
Published in Biofouling, 2019
Dong Hu, Wenfang Lin, Jie Zeng, Peng Wu, Menglu Zhang, Lizheng Guo, Chengsong Ye, Kun Wan, Xin Yu
After incubation for 30 days, the isolated fungi exhibited the ability to utilize aviation fuel (Figure S3, Supplementary material), although the metabolic capacity of these isolated fungi for aviation fuel was not as strong as expected (Figure S4, Supplementary material). Microorganisms can present different characteristics in different microenvironments (Wu et al. 2013), and different weight losses (41.6–66.9%) and degradation rates (95.8–96.57%) of aviation fuel by contaminating microorganisms have been observed in other studies (Itah et al. 2009; Omotayo et al. 2011). Regarding the oil droplets present at the fuel-water interface in the tested mineral solutions, biosurfactants might be secreted during the deterioration of the fuel by fungi (Figure S5, Table S4, Supplementary material) and decrease the surface tension of the fuel (Table S3, Supplementary material), increasing the bioavailability of the aviation fuel. In this study, a pH decrease was observed in the mineral medium for all the fungi tested (Table S3, Supplementary material). Previous studies have reported that fungi and bacteria can secrete some organic or inorganic acids (Qu et al. 2015; Dai et al. 2016; Xu et al. 2016; Li et al. 2017), especially during microbial hydrocarbon degradation (Samuel et al. 2015). The acids produced can degrade fuel quality and even attack carbon steel (Baoren and Naiyou 2004), which is a major challenge for fuel systems. More importantly, a high level of fungal contamination in this study (Table 3) and the strong adhesion growth characteristics give fungi the advantage in forming attached biofilms (Figure S3, Supplementary material), which might be harmful to fuel systems, and special attention should be paid to the walls of fuel tanks during maintenance.
Host acid signal controls Salmonella flagella biogenesis through CadC-YdiV axis
Published in Gut Microbes, 2022
Weiwei Wang, Yingying Yue, Min Zhang, Nannan Song, Haihong Jia, Yuanji Dai, Fengyu Zhang, Cuiling Li, Bingqing Li
To further determine whether acid can induce the expression of ydiV, the protein level of YdiV was detected after acid treatment (Figures 3b and 3c). Considering that the acid stress faced by Salmonella in the process of invading the host includes organic and inorganic acids, we used these two different types of acids in the experiment. As expected, YdiV was barely expressed when Salmonella was cultured in LB medium or under inorganic acid stress (HCl), whereas expression increased to a high level under organic acid stress (acetic acid and MES). The special dissociation constant and cell membrane permeability of organic acids are better than inorganic acids. Therefore, acetic acid was selected as the acid pressure in subsequent experiment. The mRNA level of ydiV was detected by RT-PCR at different time points upon acid treatment, and expression increased 5.1-, 6.9-, 3.0-, and 2.8- fold, respectively, when detected 0.5, 1, 1.5, and 2 h upon acid treatment (Figure 3d). To determine whether YdiV is related to flagellum control under acidic conditions, we next assessed the expression of flagellar genes (flhD, fliA, fliC) in ∆ydiV strain during acid adaptation. The expression levels of flhD, fliA and fliC were all remarkably up-regulated after acid treatment (Figure 3g-i), indicating that ∆ydiV lost the acid-mediated flagellum control phenotype. Furthermore, we monitored the motility behavior of WT and ∆ydiV strains at different pH. There was no obvious difference in motility behavior of WT and ∆ydiV strains at pH7.0. However, the ∆ydiV did not exhibit the severe motility defect that was observed in WT strain under acidic pH condition (Figures 3e and 3f). Together, these results suggest that YdiV exerts an important role in flagellum control upon encountering acid stress.