Microbial against

Preservatives. The carbonation and acid content ia cola and lemon—lime beverages usually act as adequate preservation against microbial growth. Benzoate or sorbate salts are often added to other beverages for protection (Table 2). 

Contamination. Manufacturers of cosmetics must be careful to guard against chemical and microbial contamination. Chemical contamination, which may result from the presence of undesirable impurities in raw materials, is avoidable by adhering to rigid specifications for raw materials. Compendial specifications and pubHcations by the CTFA and other professional societies form the basis of most intracompany raw material specifications. Moreover, all packaging components must meet not only physical and design specifications but also such chemical requirements as extractables and absence of dust and similar contaminants (see Packaging, cosLffiTics and pharmaceuticals). 

Three more antibiotics, all discovered about 1953, are also derivatives of cytosine. Amicetin, bamicetin and plicacetin may all be isolated from Streptomyces plicatus and all have some activity against some acid-fast and Gram-positive bacteria as well as some other microbial systems (69MI21301). Structural work in this area is fascinating (62JOC2991). 

Methods of protecting materials against microbial corrosion include ... 

About 5 ml of sample is withdrawn for every 4-6 hours. The absorbance reading of the sample at 580 nm was measured using a Hitachi U-2000 spectrophotometer. The sample is filtered in a vacuum through Whatman filter paper with a pore size of 2.5 pin and diameter of 47 mm. The dry weight of cells is measured to monitoring microbial cell population and cell density. A plot of optical density reading from the spectrophotometer against cell dry... 

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. 

As part of the design proeess, it is neeessary to inelude features in the formulation and delivery system to provide as mueh proteetion as possible against microbial eontaminahon and spoilage. Beeause of potenhal toxicity and irritancy problems, anhmicrobial preservatives should only be considered where there is clear evidence of posihve benefit. Manipulahon of physico-chemical parameters, such as A, the eliminahon of particularly suscephble ingredients, the selection of a preservahve or the choice of container may contribute significantly to overall medicine stability. 

For dry dosage forms, since it is their very low A which is their protechon against microbial attack, the moisture vapour properties of packaging materials requires careful examination. 

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