Dowicil 200 Stability test: chemical and microbiological studies.
Synopsis The stability of the formaldehyde-releaser preservative Dowicil 200 has been investigated. The studies were carried out on cosmetic emulsions preserved with different concentrations of Dowicil 200, stored in the dark at 45 degrees C or 25 degrees C. The degree of microbiological activity was tested with respect to S. aureus, P. aeruginosa, E. coli and A. niger using the agar diffusion and challenge tests. The chemical stability was evaluated by HPLC in the reverse phase mode. A significant preservative instability was observed.
Semenzato
A
A
Centro di Cosmetologia Chimica, Università di Padova, Via Marzolo 5, 35131 Padova, Italy.
Benassi
C A
CA
Rossi
G
G
Bettero
A
A
Lucchiari
M
M
Cerini
R
R