Class of 2009 Abstract / OBJECTIVES: The primary objective of this experiment was to characterize the pH stability range of 20% Pluronic lecithin organogel (PLO). We intended to determine the viscosity at varying pHs. We prepared six samples of 20% PLO.
METHODS: An initial rheological reading of each sample was recorded by a dynamic stress rheometer. Each sample was titrated drop-wise with citric acid or KOH in 0.5 pH increments. When the desired pH was obtained, a 0.5 mL sample was analyzed with a dynamic stress rheometer, RS-200, using Rheos software.
RESULTS: Since PLO is a non-Newtonian substance, viscosity changed relative to shear stress and we were not able to examine a correlation of pH with viscosity. Instead we inputted the data into Microsoft Excel® and plotted a shear stress versus viscosity curve for each sample to identify trends.
CONCLUSIONS: We were unable to achieve our primary objective of determining the viscosity characterization of 20% PLO at varying pHs due to the non-Newtonian nature of the material. Subjectively, we determined the viscosity of 20% PLO is not substantially affected by pH. Other factors such as temperature, excess liquid, and surfactant ability may influence viscosity and need to be examined in the future.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/623980 |
| Date | January 2009 |
| Creators | Lucht, Julie |
| Contributors | Newton, Stephen, College of Pharmacy, The University of Arizona |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Electronic Report |
| Rights | Copyright © is held by the author. |
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