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Greener Synthesis of Potential Drugs
Published in Ahindra Nag, Greener Synthesis of Organic Compounds, Drugs and Natural Products, 2022
Renata Studzińska, Renata Kołodziejska, Daria Kupczyk
An example of the use of the green NDES solvent in the esterification reaction catalyzed by Novozym 435 (lipase B from C. antarctica) is the synthesis of panthenyl monoacyl esters (PMEs), which are used in the production of pharmacological and cosmetic preparations [110]. Panthenol ((2,4-dihydroxy-N-(3-hydroxypropyl)-3,3-dimethylbutanamide called pro-vitamin of B5) was esterified with higher fatty acids such as capric, lauric, myristic, palmitic, oleic, and linoleic acids. Mixtures of panthenol with free fatty acids were seen to act as DESs that were excellent reaction media for the biocatalytic synthesis of PMEs (i.e. up to 83% conversion and 98% selectivity in the case of panthenyl monolaurate) – Scheme 12.15 [111].
Quality and safety of South African hand sanitisers during the COVID-19 pandemic
Published in International Journal of Environmental Health Research, 2023
W. de Bruin, M. C. van Zijl, N. H. Aneck-Hahn, L. Korsten
Table 3 provides a summary of the ingredients as stated on the labels of the 60 products and that were subsequently grouped into categories, i.e. disinfectants, emollients, thickeners, preservatives, surfactants, buffers, fragrances, and dyes. In 33 products, the term “denatured alcohol” (alcohol to which one or more unknown denaturing agents were added to make it unfit for oral use) was listed. The most common alcohol specified was ethanol, followed by isopropanol. Of note are the presence of triclosan in two products and 1-propanol and glutaral in two separate products. Two different quaternary ammonium compounds (QAC), benzalkonium chloride and chlorhexidine digluconate, were recorded. Typical emollients were glycerin (32 out of 60) and propylene glycol (20 out of 60), while other emollients included allantoin, Aloe barbadensis (aloe vera) leaf extract, Butyrospermum parkii (shea butter), polysorbate 20, ethylhexylglycerin, isopropyl myristate, polyethylene glycol (PEG)-40 castor oil, PEG-14 dimethicone, synthetic wax, panthenol (vitamin B5), and tocopheryl acetate (vitamin E). Thirty-five products contained carbomer (polyacrylic acid) as a thickener, and one product’s viscosity was enhanced with xanthan gum. None of the emollients or thickeners are known to produce dermal irritation and are considered safe for topical use. One product contained a UV filter that can provoke ACD, namely benzophenone-4. Altogether 11 products contained preservatives – all of them are considered safe or weak skin sensitisers, except for the two isothiazolinones (methylchloroisothiazolinone and methylisothiazolinone) that are common causal agents of ACD. The only surfactants found are mild skin irritants, namely synperonic nonylphenol and polysorbate-60. The most frequently identified buffer was triethanolamine (TEOA) (23 products), while only one product contained a buffer known to induce ACD, namely tetrahydroxypropyl ethylenediamine. Fragrances were very common. Fourteen of the 20 fragrances mentioned are established contact allergens (alpha isomethyl ionone, amyl cinnamal, benzyl benzoate, benzyl salicylate, lilial, citral, citronellol, coumarin, eugenol, geraniol, hydroxycitronellol, lavender oil, limonene and pine oil) with seven of these capable of inducing ACD. In 28 products, the term “parfum” (a fragrance composition, often consisting of 10–100 fragrance ingredients) was listed. Methyl salicylate was the only potentially harmful fragrance. Of the eight different dyes that were found, three were non-irritant and deemed safe for use. The two yellows (sunset yellow and tartrazine) are classified as asthma and allergy inducers, while the blues (sky blue and brilliant blue) may cause long-lasting harmful effects. Three endocrine disruptor compounds (EDC) were recorded, namely synperonic nonylphenol, benzophenone-4, and triclosan.