Stabilitätsbeurteilung von O/W-Cremes mit Hilfe der OszillationsrheologieTeil I Christian Rose und Rolf Daniels Assessing the Stability of O/W Creams using Oscillatory Measurements Hydrophilic Cream can deliberately be destabilized by adding electrolytes; this is thus a good model for investigating the stability of O/W creams. Assessment of the physical stability of such creams with different shelf life was performed using oscillatory measurements in combination with suitable storage conditions. Extreme storage conditions, in particular temperatures above 40 °C, destabilize the creams in excess and are therefore not predictive for the stability. Storing the samples isothermally at 40 °C or heat-cool cycling in the range from -5 to 40 °C revealed optimum results when combined with statistical approaches to the analysis of rheological data. Both storage conditions provide equivalent evidence on the stability and allow an early identification of formulations which are not sufficiently stable. Key words Creme · Ãl-in-Wasser-Emulsionen, Stabilitätsbeurteilung · Oszillationsrheologie, Phasenwinkel, Speichermodul |
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pharmind 2000, Nr. 9, Seite 726