DIMETHYLSILOXANE POLYMERS - VAPORIZATION RATE TEST FREEZING TEMPERATURES

The use of silicones in cosmetic products has increased considerably i n recent years, due to the wide field of application they exhibit. A s pecial group are the cyclomethicones, also called volatile PDMS or dim ethylcyclosiloxanes, used in multiple pharmaceutical formulations. The aim of this paper is to select a mixture of cyclic cyclomethicones wi th four and five silicon atoms, in order to obtain a product that exhi bits a suitably low solidification temperature (approx. - 10 degrees C ) and ready evaporation, combined properties that the individual cyclo methicones do not exhibit separately. Tests were carried our following the standards DIN-53170, UNE 55-902-85, and Farm.Eu. The samples were subjected to different temperatures, ranging from 40 degrees C to 80 degrees C for vaporization rate rests, and from - 10 degrees C to 4 de grees C for freezing rate rests. Results demonstrate that the mixture V-5 and DC-244 in the proportion 5:5 is the most suitable for emulsion -type formulations.