Chemical stability and microbiological reply of preservative systems in cosmetics: a direct correlation.
Synopsis The results of a chemical/microbiological comparative study on different preservative mixtures are reported. The aim of the investigation was to ascertain whether there was a correlation between chemical stability and microbiological activity. The studies were carried out directly in cosmetic emulsions preserved with different mixtures of Prevan, Bronopol, Germall 115 and Kathon CG. The degree of microbiological activity was tested with respect to E. coli, Ps. aeruginosa, Asp. niger, S. aureus using the agar diffusion test, over a period of 400 days. The chemical behaviour of the different mixtures was evaluated by HPLC in reverse phase mode. The emulsion samples were directly injected after dilution with a THF/H(2)O) (9/1) solvent mixture.
Benassi
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Dipartimento di Scienze Farmaceutiche, Universita di Padova, Via Marzolo 5, 35131 Padova.
Rettore
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Semenzato
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Bettero
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Cerini
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