Triclosan (sometimes abbreviated TCS ) is an antibacterial and antifungal agent found in some consumer products, including toothpaste, soap, detergents, toys, and surgical cleaning treatments. It is similar in its use and the mechanism of action to the triclocarban. Its efficacy as an antimicrobial agent, the risk of antimicrobial resistance, and its possible role in impaired hormonal development is controversial. Additional research seeks to understand the potential impact on organisms and environmental health.
Triclosan was developed in the 1960s. In September 2016, the FDA announced that effective in September 2017, it would ban the sale of consumer antiseptic junkies containing triclosan or 18 other materials marketed as antimicrobials due to FDA findings about the lack of efficacy in these products.
Video Triclosan
Usage
Triclosan was used as a hospital scrub in the 1970s. Since then, it has grown commercially and is now a common ingredient in soaps (0.10-1.00%), shampoos, deodorants, toothpastes, mouthwashes, cleaning agents, and pesticides. It is part of consumer products, including kitchen utensils, toys, blankets, socks, and garbage bags.
By 2017, there are five registrations for triclosan with EPA. Antimicrobial active ingredients are added to various products where it acts to slow or stop the growth of bacteria, fungi, and fungi. In the use of commercial, institutional and industrial equipment, triclosan is incorporated in conveyor belts, fire hoses, dip containers, or ice-making equipment as antimicrobials. Triclosan can be directly applied to commercial HVAC coils, where it prevents microbial growth that contributes to product degradation.
In 2000, triclosan and triclocarban (TCC) can be found in 75% liquid soap and 29% bar soap, and by 2014 triclosan is used in over 2,000 consumer products.
In health care, triclosan is used in scrub surgery and hand washing. Use in an effective surgical unit with minimum contact time of approximately two minutes. Recently, a 2% triclosan bath has been a recommended regimen in the surgical unit for the decolonization of patients whose skin contains methicillin-resistant Staphylococcus aureus (MRSA).
Triclosan is also used in coating for several surgical sutures. There is good evidence that these triclosan coated sutures reduce the risk of infection at the site of surgery. The World Health Organization, the American College of Surgeons and the Surgical Infection Society, demonstrates the benefits of triclosan-coated sutures in reducing the risk of surgical site infection.
Triclosan has been used as a selective agent in molecular cloning. Host bacteria modified by plasmids containing the triclosan-resistant mutant gene FabI (mFabI) ​​as selectable markers can grow with triclosan high doses in growth media.
Effectiveness
In surgery, the triclosan coated suture reduces the risk of infection of the surgical site. Several studies have shown that antimicrobial soap containing triclosan provides a slightly larger reduction of bacteria in the hands compared with ordinary soap. In 2013, the US FDA has found a clear health benefit for some consumer products containing triclosan, but not others; for example the FDA has no evidence that triclosan in antibacterial soaps and body washes provides any benefits over washing with soap and water.
A Cochrane review of 30 studies concluded that toothpaste containing triclosan/copolymer resulted in a 22% reduction in both dental plaque and gingival inflammation when compared to fluoride toothpaste without triclosan/copolymer. There is weak evidence of decreased cavities, and there is no evidence of reduction of periodontitis.
A study by Colgate-Palmolive found a significant reduction in gingivitis, bleeding, and plaque with the use of toothpaste containing triclosan, but an independent review of the Cochrane group showed that while gingivitis, hemorrhage, and plaque reduction may be statistically significant. , may not be sufficiently useful to produce clinical significance.
Maps Triclosan
Chemical and property structure
This organic compound is a solid white powder with a slight odor, aromatic phenolics. Classified as phenol phenokat polychloro, triclosan is chlorinated aromatic compound having functional group representing ether and phenol. Phenols often exhibit antibacterial properties. Triclosan is soluble in ethanol, methanol, diethyl ether, and very basic solutions such as 1M sodium hydroxide solution, but only slightly soluble in water. Triclosan can be synthesized from 2,4-dichlorophenol.
Synthesis
Under the reflux process, 2,4,4'-trichloro-2'-methoxydiphenyl ether is treated with aluminum chloride.
Triclosan can be synthesized by a three-step process starting with 1- (2-hydroxyethyl) pyrrolidin-2-one. The (2-hydroxyethyl) pyrrolidine-2-one was dehydrated with either zinc or calcium oxide to 1-vinylpyrrolidine-2-one. Then, 1-vinylpyrrolidine-2-one can be reacted with 5-chloro-2- (2,4-dichlorophenoxy) phenyl acrylate in n-heptane to form triclosan.
The United States Pharmacopoeia Formulary has published monographs for triclosan that set the standard of purity.
Action mechanism
At high concentrations, triclosan acts as a biocide with several targets of cytoplasm and membrane. However, at lower concentrations seen in commercial products, triclosan appears bacteriostatic, and targets bacteria primarily by inhibiting fatty acid synthesis.
Triclosan binds enoyl-acyl carrier protein reductase (ENR) enzyme, which is encoded by the FabI genes. This binding increases the affinity of the enzyme for nicotinamide adenine dinucleotide (NAD ). This results in the formation of a stable, stable complex of ENR-NAD -triclosan, which can not participate in fatty acid synthesis. Fatty acids are needed to build and reproduce cell membranes. Humans do not have ENR enzymes and are thus unaffected by this mode of action.
Endocrine disruptors
Triclosan has been found to be a weak endocrine disruptor, although this relevance to humans is uncertain. Compounds have been found to bind with low affinity for both androgen receptors and estrogen receptors, in which both agonist and antagonist responses have been observed.
Exposure
Humans are exposed to triclosan through skin absorption while washing their hands or in the bathroom, brushing, using mouthwash or washing dishes, and through ingestion when swallowed. When triclosan is released into the environment, exposure to additional chemicals is possible through ingestion of plants grown on mud-fed soils, or eating exposed fish.
An article from the American Society of Agronomy refers to a study conducted by Monica Mendez et al. , in which researchers irrigate plants with water contaminated with triclosan and a few months later find it in all parts of edible tomatoes and onion plants. Triclosan is found to kill a broad spectrum of bacteria, and researchers are also concerned about its effect on beneficial bacteria in the soil. Distribution, metabolism, and elimination
Once absorbed, triclosan is metabolized by humans primarily through conjugate reactions into glucuronide and sulfate conjugates excreted in feces and urine. Pharmacokinetic studies show that triclosan sulfate and glucuronide can form in the liver at approximately the same level at an environmentally relevant concentration of 1 to 5 microMolar. When the concentration of triclosan is below 1 microMolar, sulfonation is expected to be the main metabolic pathway for elimination.
Health issues
Due to the potential health problems ranging from antimicrobial resistance to endocrine disorders, triclosan has been defined as "causative contagion (CEC)", meaning that it is being investigated for public health risks. "Emerging contaminants" can be broadly defined as any synthetically or chemically occurring or unusual microorganisms monitored in the environment but have the potential to enter the environment and cause known or suspected adverse ecological and (or) human health effects. Triclosan is estimated to accumulate in the wastewater and return to drinking water, thus spreading the buildup that may cause increased effects with ongoing use.
In an article from May 2015 on the current status of triclosan, Gurpreet Singh Dhillon and colleagues cite various studies that report "emerging health problems associated with the use of TCS such as microbial resistance, skin irritation, endocrine disorders, higher allergic incidents, changes in thyroid hormone metabolism and tumor development due to TCS and its by-products ".
Triclosan is considered safe by some but is being reviewed by the FDA. Health Canada's review concludes "that triclosan is not harmful to human health but can cause significant environmental damage when used." This preliminary assessment ensures that Canada can continue to use products such as toothpaste, shampoo and soap containing triclosan "safely.
In the United States, following a decade-long review of the potential health problems of these emerging attention contaminants, the FDA decided on September 6, 2016, that 19 active ingredients including triclosan are not generally recognized as safe and effective (GRAS/GRAE)). [See policy section below].
Allergic
Triclosan has been associated with a higher risk of food allergies. This may be because exposure to bacteria reduces allergies, as predicted by the hygiene hypothesis, and is not caused by the toxicology of triclosan itself. This effect can also occur with chlorhexidine gluconate and PCMX, among other antibacterial agents. Other studies have linked triclosan to allergic contact dermatitis in some individuals. In addition, the concentration of triclosan has been associated with allergic sensitization, particularly inhalant and seasonal allergens, rather than food allergens.
By-products
Triclosan can react with free chlorine in chlorinated tap water to produce less amounts of other compounds, such as 2,4-dichlorophenol. Some of these intermediates are converted into dioxins after exposure to UV radiation (from the sun or other sources). Dioxins that may form from triclosan are not considered to be a toxicological concern for mammals, birds and fish.
Cardiovascular Disease
The use of triclosan-toothpaste may not be associated with an increased incidence of serious heart disease.
Hormones
Concerns about the health effects of triclosan have increased after being detected in breast milk, blood, and urine samples. Studies in mice showed that exposure to triclosan modulated an estrogen-dependent response. There have been many studies conducted over the years both in vivo and in vitro, in fish and male and female rats and they all support the conclusion that triclosan has both anti-estrogenic and (anti) androgenic properties depending on species, tissues and cells type. In a 2017 study of 537 pregnant women in China, exposure to prenatal triclosan was associated with elevated testosterone levels in infants.
History
Triclosan (TCS) was patented in 1964 by the Swiss company Ciba-Geigy. The most well known safety tests began in 1968. It was introduced next year, primarily for use in hospitals, and in production and use worldwide in the early 1970s.
In 1997 Ciba-Geigy joined another Swiss firm, Sandoz, to form Novartis. During the merger, Ciba-Geigy's chemical business was spun into Ciba Specialty Chemicals, which was acquired in 2008 by chemical giant BASF. BASF currently produces TCS under the trademark Irgasan DP300.
Environmental issues
Treatment and disposal
The duration of triclosan in the use of personal products is relatively short. After disposal, triclosan is sent to a municipal sewage treatment plant, where about 97-98% of triclosan is removed. Studies show that large numbers of triclosan (170,000-970,000 kg/year) can penetrate wastewater treatment plants and damage algae on the water surface. In a study of effluents from wastewater treatment facilities, about 75% of triclocarban are present in the mud. This poses potential ecological and environmental hazards, especially for aquatic systems. The volume of triclosan re-entering the environment in the sewage sludge after successful initial successful capture of wastewater is 44,000 Ã, Â ± 60,000 kg/year. Triclosan may be attached to other substances suspended in the aquatic environment, potentially harmful to marine organisms and may cause further bioaccumulation. Ozone is considered an effective tool for removing triclosan during waste treatment. Because small triclosan is released through household consumer products of plastics and textiles, this is not considered a major source of triclosan contamination.
During wastewater treatment, a portion of the triclosan is degraded, while the residual adsorption to the sewage sludge or leaves the plant as waste. In the environment, triclosan can be degraded by microorganisms or react with sunlight, forming other compounds, which include chlorophenols and dioxins.
During 1999 to 2000, the US Geological Survey detected TCS in 57.6% of river flows and river samples.
Bioaccumulation
While research using a semi-permeable membrane device has found that triclosan is not highly bioaccumulated, methyl-triclosan is relatively more stable and lipophilic and thus carries a higher bioaccumulation risk. The ability of triclosan for bioaccumulation is affected by ionization status under different environmental conditions.
Global warming can increase the uptake and effects of triclosan in aquatic organisms.
Ecotoxicity
Triclosan is toxic to water bacteria at levels found in the environment. It is highly toxic to different types of algae and has the potential to affect the structure of algal communities, especially immediately downstream of waste from wastewater treatment facilities that treat domestic sewerage. Triclosan has been observed in a variety of organisms, including algae, black water worms, fish, and dolphins. It has also been found in terrestrial animals including earthworms and higher species of food chains.
Triclosan likes the typical anaerobic conditions in soil and sediment. The antimicrobial properties of Triclosan are resistant to anaerobic degradation which is a major contributor to persistence in the environment.
Concerns about resistance
Concern regarding the potential for cross resistance or mutual resistance to other antimicrobials. A number of studies have been conducted and there are results suggesting that the use of biocidal agents, such as triclosan, can cause cross resistance. The results of a study published in The American Journal of Infection Control show that exposure to triclosan is associated with a high risk of developing resistance and cross-resistance in Staphylococcus aureus and Escherichia coli . This was not observed with exposure to chlorhexidine or hydrogen peroxide based agents (during the conditions in the study).
Alternative
A comprehensive analysis in 2007 from the University of Michigan School of Public Health showed that ordinary soaps are as effective as consumer-level antibacterial soaps with triclosan in preventing disease and removing bacteria from the hands.
Non-organic antibiotics and organic biocides are an effective alternative to triclosan, such as silver and copper ions and nanoparticles.
Policy
In the US, triclosan is regulated as a pesticide by the EPA and as a drug by the FDA. The EPA generally regulates use on solid surfaces, and FDA regulations include use in personal care products.
In 1974, the US FDA initiated a process of reviewing drug monographs for "topical antimicrobial products (over-the-counter)," including triclosan and triclocarban. The advisory panel first met on June 29, 1972, and the agency published the proposed rule on September 13, 1974. The initial rule applies to, "OTC products contain antimicrobial ingredients for topical human use, which include soaps, surgical scrubs, leaching, skin, first aid preparation and auxiliary products determined by the panel. "The proposed rule contains dozens of products already in the market at the time and the companies that produce them.
In 1978 the FDA published a provisional final monograph (TFM) for topical antimicrobial products. The record was reopened in March 1979 to consider six comments received by the agency during that period to file an objection to TFM, including new data sent by Procter & amp; Gambling about the safety and effectiveness of triclocarban and by Ciba-Geigy about the proliferation of triclosan use. The document states that, "a large amount of new and previously unknown data is sent with each of the above petitions." It reopened again in October of that year to allow anyone interested in submitting further data establishing conditions for the safety, effectiveness and labeling of topical antimicrobial products sold freely for human use.
The subsequent document issued is a proposed rule dated June 17, 1994, stating, "The FDA issues a notice of the proposed legislation in the form of an amended, temporary final monograph which will establish the conditions under which topical antiseptic OTC health care products are generally recognized as safe and effective and not misbranded. The FDA issued this notice proposing regulation on topical antimicrobial drug products after considering public comments on the notice and other information in the administrative records for the drafting of this regulation.The FDA also requested data and information on the safety and effectiveness of topical antimicrobials for use as hand sanitizers or dips. "In 1994 the regulatory update, TCS was effectively removed from the drug category that made it available for use in consumer products.
In 2010, the Natural Resources Defense Council forced the FDA to review triclosan after prosecuting them for their inaction. Because the FDA prohibits hexachlorophene, a compound similar to triclosan, Halden and others argue that the FDA should also forbid triclosan. On December 17, 2013, the FDA issued a draft revocation regulation that is generally recognized as the safe status of triclosan as an ingredient in handwashing products, citing the need for additional studies of the potential for endrocrine and its developmental effects; impact on bacterial resistance; and carcinogenic potential.
On September 6, 2016, 44 years after the proposed initial rule, the FDA issued a final rule stipulating that 19 active ingredients, including triclosan and triclocarban, are used in over-the-counter consumer antiseptic products (OTC) intended for use with water (aka washing consumer antiseptics) are generally not recognized as safe and effective (GRAS/GRAE) and misbranded, and are new drugs for approved applications under section 505 of FD & amp; C Act is required for marketing. The Company has one year to redefine the product without these materials, remove it from the market or submit a New Drug Application (NDA) for the product. 19th such materials are: oCloflucarban oFluorosalan oHexachlorophene oodine oHexylresorcinol complex (ether ammonium sulfate and polyoxyethylene sorbitan monolaurate) oodin complex (phosphate ester of alkilaryloxy polyethylene glycol) oMethylbenzethonium oNonylphenoxypoly chloride (ethyleneoxy) ethanoliodine oPhenol (more than 1.5 percent) oPhenol ( less than 1.5 percent) oPoloxamer-iodine complex oPovidone-iodine 5 to 10 percent oSecondary amyltricresols oSodium oxychlorosene oTribromes oTriclocarban oTriclosan oTriple dye oUndecoylium chloride iodine complex
In 2015 and 2016 the FDA also issued a proposed regulation to amend TFM 1994 on the safety and effectiveness of antiseptic OTC health services and consumer antiseptics.
The state of Minnesota takes action against triclosan before the federal rule. In May 2014, the governor signed a bill banning products containing triclosan in the state. The article CNN cites the new law, "To prevent the spread of infectious diseases and infections that can be avoided and to promote best practices in sanitation, no one will offer retail sales in Minnesota any cleaning products containing triclosan and used by consumers to clean or clean the hands and body. "The law comes into force on 1 January 2017. The exception to this rule is individual products that have received approval from the US Food and Drug Administration for consumer use.
Given the growing evidence of human health and the ecotoxic effects of triclosan, some companies formulated to remove it before regulation: Colgate-Palmolive removes it from Palmolive Dish Soap and Softsoap in 2011 (but remains in Colgate Total toothpaste); Johnson & amp; Johnson removes it from baby products by 2012 and all products in 2015; Procter & amp; Gamble of all products in 2014; In 2014 removed from Clearasil and Avon begin phasing it; and Unilever removes it from skin care and cleaning products by 2015, and says mouth care by 2017.
In Canada, triclosan is allowed in cosmetics, although the recent FDA announcement has prompted Health Canada spokeswoman Maryse Durette to state in an e-mail to Toronto's Globe and Mail newspaper that, "the government will publish end of the 'triclosan' security assessment in the near future 'and take further action' if needed. ' "Health Canada maintains a List of Cosmetic Basic Materials, including hundreds of chemicals that are not allowed or whose use is restricted in cosmetics. The list states that triclosan is currently allowed in cosmetics up to 0.3%, and 0.03% in mouthwash and other oral products with the warning needed to avoid swallowing and not for use in children under 12 years of age.
Triclosan is not approved by the European Commission as an active ingredient for use in biocide products for type-1 products in January 2016. In the United States, producers of triclosan-containing products must indicate their presence on the label. In Europe, triclosan is regulated as a cosmetic preservative and should be listed on the label. The use of triclosan in cosmetic products is limited by EU commissions by 2014.
See also
References
Source of the article : Wikipedia
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