Week 9: Testing

Based on the results of the last batch of experiments, a new experiment was set up using higher bromelain levels in order to detect difference in absorbance using the spectroscopic equipment acquired.  Figure 1 shows Justin adding samples to a cuvette for testing. The higher concentration calibration curve is pictured below in figure 2. All of the concentrations were visible, proving that the detection of bromelain is possible using spectrophotometry. 

Figure 1: Group member Justin Li conducting spectrophotometry tests

Figure 2. Absorbance Calibration Curve

From there the experiment was conducted once again with two varying densities: .5% wt and 1% wt alginate solution. The bromelain/alginate beads were placed in only 50cc's of water as opposed to 1000ccs. This was done to increase the concentration of bromelain in solution so that it could be more easily detected by the equipment another strategy that was used to increase concentration was simply to increase the number of beads in solution, however the dosage was reduced slightly. All of the other variables from the last experiment were held constant (Temperature, stirring, and sample collection).Samples were collected every half hour for 4 hours, with two additional samples being collected after 15 minutes had passed, and at the 5 hour mark. This was done to assure the release was entirely collected. Figure 3 shows the release rate of the .5% wt beads.

Figure 3. Bromelain release over time

As seen in Figure 3 the relase was controlled fairly well and a fairly linear release was gathered, however it appears the experiment was curtailed too quickly. The experiment should have been run until a leveling off occurred. The original parameter of 4 hours was chosen because the stomach empties every four to six hours. But, the drugs longevity was unexpected. In future testing samples will be gathered for a longer period of time.