Preservatives product contamination

Specifications and Packaging. Aluminum chloride s catalytic activity depends on its purity and particle size. Moisture contamination is an important concern and exposure to humid air must be prevented to preserve product integrity. Moisture contamination can be deterrnined by a sample s nonvolatile material content. After subliming, the material remaining is principally nonvolatile aluminum oxide. Water contamination leads to a higher content of nonvolatile material. 

Pharmaceutical manufacturers may justly argue that their responsibility ends with the supply of a well-preserved product of high microbiological standard in a suitable pack and that the subsequent use, or indeed abuse, of the product is of little concern to them. Although much less is known about how products become contaminated during use, there is reasonable evidence that continued use of such products is undesirable, particularly in hospitals where it may result in the spread of crossinfection. 

Foods. The determination of antioxidants and food preservatives is a very active part of the gas chromatography field. Adaptations and sample types are almost limitless for example, analysis of fruit juices, wines, beers, syrups, cheeses, beverages, food aromas, oils, dairy products, decomposition products, contaminants, and adulterants. A detailed discussion of this field may be found in Chapter 9. 

Formaldehyde can occur in chemical products as a component added directly in the manufacturing process or as a component added in raw materials. Some components can release formaldehyde as part of their function in the products, i.e., formaldehyde releasing preservatives (Flyvholm and Andersen 1993). Besides these intentional occurrences of formaldehyde, it can occur as residues from synthesis of other product components and from formation during storage and handling of raw materials or end products. Contamination from packages coated with formaldehyde resins has also been reported. 

An entirely different type of contamination arises from the presence of microbiota in a product. As in the case of chemical contamination, compendial requirements for microbiological purity exists. Pharmacopoeial standards vary from country to country, and manufacturers must use the specifications and kill times that meet local requirements. As of this writing, the criteria in the British Pharmacopoeia are more stringent than those estabUshed by the CTFA, which are stricter than those in the United States Pharmacopoeia. In order to meet commonly accepted standards of microbial purity, manufacturing faciUties must be periodically cleaned and all products that can support microbial growth must contain an effective preservative (6). 

Decorative eye cosmetic products have been reported to be subject to pathogenic microbial contamination. Regulatory agencies in several countries, therefore, permit the use of mercury-containing preservatives in eye makeups. The infections reported were to a large extent caused by contamination during use, and the introduction of self-sterilising preparations seems warranted. 

Where applicable, preservation processes should require that the product be cleaned before being packed and preservative applied. In other cases the product may need to be stored in sealed containers in order to retard decay, corrosion, and/or contamination. 

Tinned copper and copper alloys Copper itself has a fair corrosion resistance but traces of copper salts are often troublesome and a tin coating offers a convenient means of preventing their formation. Thus copper wire to receive rubber insulation is tinned to preserve the copper from sulphide tarnish and the rubber from copper-catalysed oxidation, and also to keep the wire easily solderable. Vessels to contain water or foodstuffs, including cooking vessels, water-heaters and heat exchangers, may all be tinned to avoid copper contamination accompanied by possible catalysis of the oxidation of such products as milk, and discolouration in the form of, for example, green stains in water and food. 

Packaging Similarly, information on the closure/packaging systems must be provided in terms of material specification, suitability/compatibility with the pharmaceutical product, dimensional specifications, water impermeability, and so on. Defence against microbial contamination should be discussed in the context of either packaging of sterile product or use of preservatives as appropriate. 

Emulsions, especially oil-in-water emulsions which, incidentally, figure widely in cosmetic products, are especially prone to failure because the preservative may partition into the oily phase of the emulsion while contaminants will flourish in the aqueous phase now deprived of preservative by partitioning (see Chapter 18 for further details). 

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