Antimicrobial Preservative Efficacy and Microbial Content Testing*
Philip A. Geis in Cosmetic Microbiology, 2020
In a capacity study by Barnes and Denton (58), the mixed cultures consisted of: (1) Gram-negative bacteria (Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens), (2) Gram-positive bacteria (Staphylococcus aureus, S. albus, Micrococcus flavus, M. luteus), (3) aerobic spore formers (Bacillus subtilis, Bacillus cereus, Bacillus megaterium), (4) mold spores (Mucor plumbeus, Aspergillus brasiliensis, Cladosporium herbarum, Penicillium spinulosum, Trichoderma spp.), and (5) yeasts (Saccharomyces cerevisiae, Sporobolomyces spp., Schizosaccharomyces pombe, Candida albicans). The preservatives tested included benzalkonium chloride, Bronopol, chlorhexidine gluconate, chlorocresol, Dowicil 200, methyl parabens, Phenonip, propyl parabens, thimerosal, and “Preservative C”. Barnes and Denton incorporated the preservatives into creams, suspensions, or solutions at recommended use levels and also tested two lower concentrations.
Antimicrobial preservative efficacy and microbial content testing
Philip A. Geis in Cosmetic Microbiology, 2006
In a capacity study by Barnes and Denton,52 the mixed cultures consisted of: (1) Gram-negative bacteria (Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens), (2) Gram-positive bacteria (Staphylococcus aureus, S. albus, Micrococcus flavus, Sarcina lutea), (3) aerobic spore formers (Bacillus subtilis, Bacillus cereus, Bacillus megaterium), (4) mold spores (Mucor plumbeus, Aspergillus niger, Cladosporium herbarum, Penicillium spinulosum, Trichoderma spp.), and (5) yeasts (Saccharomyces cerevisiae, Sporobolomyces spp., Schizosaccharomyces pombe, Candida albicans). The preservatives tested included benzalkonium chloride, Bronopol, chlorhexidine gluconate, chlorocresol, Dowicil 200, methyl parabens, Phenonip, propyl parabens, thimerosal, and “Preservative C.” Barnes and Denton incorporated the preservatives into creams, suspensions, or solutions at recommended use levels and also tested two lower concentrations.
Formulation aspects of the preservation of hair and skin products
R. M. Baird, S. F. Bloomfield in Microbial quality assurance in cosmetics, toiletries and non-sterile Pharmaceuticals, 2017
This material, often referred to by the proprietary name Bronopol, is sometimes reported to be a formaldehyde donor but is thought not to operate via this breakdown product. It has a wide spectrum of activity, particularly against Gram-negative bacteria, is water soluble and is compatible with most ingredients. The optimum pH range for activity is 5–7. However, as a nitrite donor, this material has been suggested to assist, under appropriate conditions, in the formation of nitrosamines in the presence of secondary amines.
Repurposing existing drugs: identification of irreversible IMPDH inhibitors by high-throughput screening
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Albertus Eka Yudistira Sarwono, Shinya Mitsuhashi, Mohammad Hazzaz Bin Kabir, Kengo Shigetomi, Tadashi Okada, Fumina Ohsaka, Satoko Otsuguro, Katsumi Maenaka, Makoto Igarashi, Kentaro Kato, Makoto Ubukata
From the screening process, three compounds were identified as irreversible inhibitors of IMPDH: disulfiram, bronopol, and ebselen. Disulfiram has been known as an alcohol aversion drug which acts as inactivator of acetaldehyde dehydrogenase. Intake of disulfiram together with alcohol resulted in the accumulation of acetaldehyde, causing discomforting symptoms thus discouraging further intake18. Bronopol was utilized as antiseptic and antifungal compound in aquatic veterinary settings and preservative in cosmetic products19,20. Ebselen has been known as a compound with broad activities, such as anti-inflammatory, anti-atherosclerotic, antibacterial, and anticancer. This compound has also been subjected into clinical trials for acute ischemic stroke and prophylactic neuroprotective21–27. Each inhibitor was reported previously as an irreversible inhibitor of cysteine, although with other different target enzymes19,20,28–31. Therefore, this study is the first report on the compounds as IMPDH inhibitors.
Undeclared formaldehyde levels in patient consumer products: formaldehyde test kit utility
Published in Cutaneous and Ocular Toxicology, 2019
Jason E. Ham, Paul D. Siegel, Howard Maibach
Several studies have identified additional hydrolysis products from formaldehyde releasers. (4-hydroxymethyl-2,5-dioxo-imidazolidine-4-yl)-urea (HU), (3,4-bis-hydroxymethyl-2,5-dioxo-imidazolidine-4-yl)-urea (BHU) were as major decomposition products in cosmetics from both diazolidinyl urea and imidazolidinyl urea11,12. The authors suggested that patch testing with HU and BHU should be performed, but provided no data with respect to the allergenicity of these compounds. Kireche et al. (2010) reported that DMDM hydantoin was directly reactive toward amino acids, while the bronopol and methenamine breakdown products, bromoethanol and diaminomethane, respectively, were amino acid reactive13. Bronopol is a known contact allergen14, and while we found no reports of diaminomethane allergy, diaminoethane (ethylenediamine) is a known contact allergen15. This suggest potential non-formaldehyde protein haptenation/allergic contact dermatitis products containing these formaldehyde releasers.
Related Knowledge Centers
- Bacteria
- Cosmetics
- Organic Compound
- Preservative
- Shampoo
- Toxicity
- Antimicrobial
- Medication
- Gram-Negative Bacteria
- Hydrocarbon Exploration