Rheological properties of progesterone microemulsions: Influence of xanthan and chitosan biopolymer concentration

Autor: M. Herraez, M. Dolz, Francesco Corrias, O. Diez-Sales
Rok vydání: 2008
Předmět:
Zdroj: Journal of Applied Polymer Science. 110:1225-1235
ISSN: 1097-4628
0021-8995
DOI: 10.1002/app.28657
Popis: In this preformulations study, rheological properties of microemulsions with progesterone (1%) were studied to analyze the effect of xanthan and chitosan at different concentrations (0.5–3%). Steady shear and oscillatory rheological properties were analyzed using a controlled stress rheometer. Steady shear data were satisfactorily adjusted to the Carreau model. For all preparations, shear-thinning behavior was observed. Zero shear viscosity (η0) increased with the biopolymer concentration. The results from dynamic experiments showed the behavior of all preparations with xanthan gum and those of chitosan to be characteristic of weak gels and liquid-like solutions, respectively. The correlation between dynamic and steady-shear properties (extended Cox-Merz rule) was satisfactory for the two polymers. The recovery analysis of microemulsions with xanthan showed a total recovery percentage of 90% for the highest concentrations of this polymer. However, microemulsions with chitosan showed practically no recovery. Progesterone release was greater for the microemulsions with chitosan. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Databáze: OpenAIRE