title: [The use of preservatives in skin preparations].
abstract: Dermatological preparations may be contaminated during their manufacture and their use. On account of the danger of this contamination, different Pharmacopoeia prescribe the maximal allowable number of microorganisms in the different dermatological preparations. The preservatives used must kill or diminish their number in a period of time equal to the time elapsed between two applications. This time however could be different for each preparation. Therefore the preservatives must have antibacterial activities adapted to the use of the dermatological preparation. The activity can be given by the D-value or the decimal reductiontime. The D-values of the different kinds of dermatological preparations have been calculated with a startcontamination of 10(6) microorganism g. The activity of a preservative must be determined directly in the preparation. Firstly the preparation with a preservative is contaminated with microorganisms, secondly the killing rate is determined and finally the D-value is calculated. After the calculation of the D-value of different samples each containing a different preservative and several concentrations, it is possible to select a preservative and to determine his concentration giving a D-value corresponding to the D-value required by the use of the dermatological preparation.
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage; D004340:Drug Contamination / Q000517:prevention & control; D004352:Drug Resistance, Microbial; D006801:Humans; D010592:Pharmaceutic Aids; D011310:Preservatives, Pharmaceutical
chemical_list: D000891:Anti-Infective Agents, Local; D010592:Pharmaceutic Aids; D011310:Preservatives, Pharmaceutical
vernacular_title: Der Gebrauch von Konservierungsmitteln in Dermatica.