Stability evaluation of thermosensitive drug carrier systems based on Pluronic F-127 polymer.

ABSTRACT

The aim of this study was to evaluate the stability of thermosensitive systems based on Pluronic F-127 polymer, in aspects of their possible application in novel drug technology. A formulation was prepared without any active ingredient, consisting of 16% (w/w) of polymer dissolved in aqueous medium. Such preparation was autoclaved and then subjected to 3-month conditioning at elevated (40 degrees) and reduced (5 degrees C) temperature. Rheological parameters viscosity, consistency and sol-gel transition characteristics were studied in 1-month interval. The significance of measured changes was evaluated by proper statistical analyses. Significant changes exceeding the established criteria (+/- 10% of every initial value) were observed during the study. Furthermore, total involution of sol-gel transition phenomenon was observed in samples stored at 40 degrees C. Results indicate the lack of stability in tested formulation at both of storage conditions. However, some regularity indicates that the stability at reduced temperature could be confirmed, if only the concentration of polymer and the measurements schedule were slightly modified.