Antimicrobial additives

Antimicrobial agents have mostly low molecular weight molecules that kill or suppress the growth of viruses, bacteria, or fungi. Molecular aspects on the action of antimicrobial agents have been compiled in the literature (2). An activity against viruses is of minor interest in the polymer industry. A markable exception is in the field of medical applications. 

Common antimicrobials and their listed below. Details can be found 

Although mould growth is a great problem with bread, and it is this group of organisms that usually limits the shelf-life, it is vital to prevent a reduction of this shelf-life by growth of the rope bacterium, hence antimicrobials are added to bread in many countries. 

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Medicated Dandruff Shampoos. Dandmff is a scalp condition characterized by the production of excessive cellular material (18). A number of shampoos have been marketed which are designed to control and alleviate this condition, and many additives have been included in shampoo compositions to classify them as treatment products for dandmff. These additives include antimicrobial additives, eg, quaternary ammonium salts keratolytic agents, eg, saUcychc acid and sulfur heavy metals, eg, cadmium sulfide coal tar resorcinol and many others. More recent (ca 1993) systems use selenium sulfide [7488-56-4] or zinc pyrithione [13463-41 -7] as active antidandmff shampoo additives. Both of these additives are classified as dmgs, but can be found in over-the-counter products. A stronger version, incorporating the use of higher levels of selenium sulfide in a shampoo, is available but requires a prescription for purchase. 

Miscellaneous, New, and Developmental Antimicrobial Agents. Table 11 shows some of the antimicrobials that do not neady fit into the principal families. Acrolein (qv) is a unique chemical used for secondary oil recovery (43). Biobor has become the antimicrobial addition of choice for aviation fuels (44). Cbloropbtbalonil (tetrachloroisophthalnitrile [1897-45-6]) is a significant agricultural fungicide, in addition to being one of the most important latex paint film preservatives (producer, ISK). 

Disinfectant Formulations and Sterilization. Hundreds of appHcations covering disinfectant compositions using sodium chlorite have been described in U.S. and foreign patents. Some examples of these are as antimicrobial additives for latexes (166), marine antifouling agents (see Coatings, marine) (167,168), antimildew detergent compositions (169), toothpaste and solution compositions for prevention and treatment of periodontal oral disease (see Dentifrices) (170—172), and compositions for the disinfection of contact lenses (qv) (173). 

Bisulfite Adduct. A bisulfite addition complex of an aldehyde or dialdehyde has been proposed for use as an antimicrobial agent [1858,1859]. The complex is less toxic than free glutaraldehyde. In oil wells, its digestion by the sulfate-reducing bacteria releases the free dialdehyde that controls the bacteria. In these ways, a more economic and environmentally safer use of antimicrobial additives is likely. 

Antimicrobial additives can be used in polymeric materials to prevent or reduce the growth of bacteria and other organisms. A common antimicrobial agent is 2,4,4 -trichloro-2 -hydroxydiphenyl ether also known as triclosan. Its presence can be detected using combined GC/MS (Figures 8 and 9). 

In the field of muscle foods, the use of marination before irradiation reduced the dose necessary to eliminate Salmonella in poultry [113]. Some antimicrobial additives, especially the natural ones (e.g., bacteriocins) [94] and GRAS (generally recognized as safe) preservatives [114] can be usefully combined with irradiation to reduce dose requirements. Some antioxidants have also been used to prevent the undesirable oxidative effects in irradiated foods. 

According to the food laws and regulations of the Food and Drug Administration (FDA), organic acids can be used as acidulants (e.g., citric, fumaric, malic, and sorbic acid), antimicrobial additives (e.g., propionic acid), and sequestrants (e.g., tartaric acid) (14). Most fatty acids of... 

Han, J., and Washington, C. (2005), Partition of antimicrobial additives in an intravenous emulsion and their effect on emulsion physical stability, Int. J. Pharm., 288, 263-271. 

The use of antimicrobial additives has been mentioned in section 12.7.2, but another route has also been investigated, the deposition of silver nanoparticles, under formaldehyde-radio frequency plasma conditions, onto food-grade silicone rubber. The bacteriocidal properties of the silver-coated surfaces were investigated by exposing them to Listeria monocytogenes, with no bacteria being detected after exposure times of 12 to 18 hours. 

Metallic salt and paraffin wax emulsion with antimicrobial additives. Special water-repellent agent for glass fiber fabrics. Used in combination with SARPIFAN BKF in the stiffening process of glass fiber fabrics. 

Three types of packages are defined for injectable medications. The first, the bulk package, has very few restrictions. The closure must be sterile and should be penetrated only once following the filling. The container should only be violated under sterile conditions, no antimicrobial additive is necessary, and no volume restrictions apply. 

The second type of container is the single-dose container. This container should contain a quantity designed for a single-parenteral preparation (not to exceed 1 L) and should contain a suitable antimicrobial additive. Larger packaging volumes may be used for compounds designed for use with hemofiltration, dialysis, or parenteral nutrition. 

Multiple-dose containers constitute the third type of package used with parenteral medications. These containers can deliver more than a single dose for more than a single patient, but are not to permit the withdrawal of more than 30 mL unless otherwise specified in the applicable monograph. Intraspinal, intracister-nal, and peridural drugs should not be packaged in multiple-dose containers, and these packages should also contain a suitable antimicrobial additive. 

The antimicrobial additive may be applied in a controlled way where material is not lost, such as incorporation into the food-contact layer of a multilayer packaging material. 

To apply an antimicrobial additive in a controlled matter where the material is needed and not lost. 

Bobey DG, Russell AD, and Jones CB. Selection of Disodium Edetate as the Optimal Antimicrobial Additive for Use in Propofol Emulsion. Pharm Ther 2001 11 335-341. 

There is a recognised need for antimicrobial additives in plastics and all types of surface coatings to maintain then-integrity and appearance. The current available laboratory test methods do not always provide a good indication of performance and some could be open to misinterpretation. In addition, the use of additives for claims of antibacterial... 

TAPPI Hot Melt Symposium 2002. Proceedings of a conference held Charlotte, NC., 23rd-26th June 2002. Atlanta, Ga., TAPPI Press, 2002, p.73-7,28cm, 012 ANTIMICROBIAL ADDITIVES FOR ADHESIVE APPLICATIONS EarhartN... 

Plastics Additives and Conq>ounding 3,No.l2, Dec. 2001,p.l6-8 ANTIMICROBIAL ADDITIVE SYSTEMS SEE INCREASED USE IN POLYMERS... 

The increasing use of antimicrobial additive systems by the plastics industry is discussed, and examples are described in which they are beneficial in providing added value and product differentiation. Particular reference is made to Wells Plastics, which has developed a range of inoi nic, mainly silver ion antimicrobial products. These are based upon a technology that encapsulates the silver ions in a soluble matrix, which protects the silver ions during then-processing and controls their release. Case studies involving the provision of antimicrobial solutions are included. 

Cellulose based plastics and certain PVC formulations are vulnerable to attack from microorganisms. Specific biocides are targeted at particular organisms and can be more precisely defined as bactericides, fungicides, etc. Antimicrobial additives are now widely used in polyolefin kitchenware and bathroom accessories to act in defence of substances coming into contact with the polymer. EUROPEAN COMMUNITY EUROPEAN UNION UK WESTERN EUROPE... 

The diphenyl ether triclosan, an antimicrobial additive in many personal care products, is a potent inhibitor of the FabI enzymes from E. coli, S. aureus, and P. falciparum (see Lu and T onge, and references therein). Similar to the diazaborine inhibitors, binding of triclosan to ecFabI in the presence of NAD" " results in ordering of the substrate-binding loop (Figure 25). Kinetic studies have shown that triclosan is a slow-onset inhibitor of... 

Nisin is not the only antimicrobial additive that was recently added to cellulose films. Pediocin (ALTA 2351), another antimicrobial peptide, from Pediococcus sp, was investigated by Santiago-Silva et al. [40] for its activity in a cellulose emulsion against L. innocua and Salmonella sp. Using processed meat products, cellulose films containing 25% and 50% pediocin were placed on sliced ham that had been immersed in the bacterial solutions. Incubation was carried out under vacuum and at 12°C for 0-15 days. The team found the 50% pediocin-containing cellulose films reduced the growth of L. innocua by 2 log cycles after 15 days of incubation. Reduction in Salmonella sp. however was low at 0.5 log cycle after 12 days for both 25% and 50% pediocin concentrations [40]. 

The increasing occurrence of microbial and nosocomial infection has stimulated research activities into antimicrobial polymers and textiles [19, 25, 34]. Most medical textiles and polymeric materials used in hospitals are conductive to crosstransmission of diseases, as most microorganisms can survive on these materials for hours to several months [17, 26]. Thus, it would be advantageous for polymeric surfaces and textile materials to exhibit antibacterial properties so as to reduce and prevent disease transmission and cross-contamination within and from hospitals. N-halamines exhibit a similar antimicrobial potency to chlorine bleach, one of the most widely used disinfectants, but they are much more stable, less corrosive and have a considerably reduced tendency to generate halogenated hydrocarbons, making them attractive candidates for the production of antimicrobial polymeric materials. N-halamine compounds are currently used as antimicrobial additives to produce polymers with antimicrobial and biofilm-limiting activities. 

The majority of all antimicrobial additives are used in flexible PVC. The remaining portion is used in polyurethane foams and other resins. PVC applications using antimicrobials include flooring, garden hose, pool liners, and wall coverings. 

Rosato D. Emerging antimicrobial additive technology, industry web report (www.specialchem4polymers.com). SpecialChem S.A. 2008 (downloaded 10 September 2008). 

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