Class: BE210
Group: 101_B2
Members:

Laurence Bell
Lajja Desai
Cindy Lau
Christopher Shen
Bo Zhou

Powerpoint Presentation
Full Text

The primary objective of this experiment is to determine the optimal pH for aspirin dissolution and whether it corresponds to the pH of the stomach.  It is hypothesized that the optimal pH for aspirin dissolution will be in the range of 1 to 3, which corresponds to the pH range of a typical stomach. This is based upon knowledge that aspirin typically dissolves in the stomach, which has a more acidic environment than other areas of the digestive system such as the small intestine (Appendix Figure 1).  Many factors besides pH, such as churning motion and digestive enzymes, however, can account for the high dissolution rate of aspirin in the stomach.  For this reason, it is necessary to have eight different pH buffer solutions instead of only two solutions: one of pH corresponding to the stomach and one of pH corresponding to the small intestine.  Keeping variables such as temperature and time of dissolution constant between the solutions, solely the effects of pH on aspirin dissolution can be observed. 
The multiple solutions will also allow for a determination on whether pH significantly contributes to aspirin dissolution even if there are other physiological characteristics of the digestive tract that can affect the process.  If the rate of dissolution is significantly different (through the use of t-tests) at the pH range of the stomach than at the pH of other regions of the digestive tract (such as 6 to 8 of the small intestine), then it can be concluded that the lower pH of the stomach is a significant factor for its higher rate of dissolution.   If optimum pH cannot be found, a relationship between pH and rate of dissolution may still be formed.  It is expected that this relationship be linear.  Based on literature information, the hypothesis will be made that pH has a proportional effect on the rate of dissolution (Appendix Figure 2).