This week, we met up over the weekend with our mentor, Pedro, to experiment with the goal of testing the effects of various concentrations of sodium alginate on the release rate of the drug. First, we created a stock solution of Methylene Blue (a blue dye) by mixing a known mass into a one liter volumetric flask. Then, we diluted the solution to create 7 total dye mixtures (5 initially, 2 additionally) with varying concentrations that would allow us to create a calibration curve. We ran each sample through the UV spectrometer and recorded the spectrum data. Once we had our molar absorption amounts, we could test the release rate of the alginate. We created three different concentrations of alginate solution and mixed them with a calcium chloride solution of a known concentration. We mixed the alginate in a solution with dye so we could measure the concentration of dye in the colorless calcium chloride solution as they dissolved. We created three solutions, and withdrew a sample from each one every six minutes for an hour. We then plotted this data to determine the release rates.
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| We prepared a range of concentrations (mg/L) of methylene blue with distilled water (left to right - greatest to least). |
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| We mixed methylene blue with sodium alginate (after collecting absorbance data for the different concentrations of methylene blue with the UV/vis spectrophotometer). |
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| It was necessary to heat up the mixture of methylene blue and sodium alginate to speed up the dissolving process. |
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| These three beakers contained unique concentrations of sodium alginate with methylene blue (as seen, concentrations of sodium alginate used included 0.75 mg/L,1.00 mg/L, and 1.25 mg/L). |
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| This is an overhead view of the beakers of methylene blue and sodium alginate. |
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| Once the sodium alginate and methylene blue was thoroughly mixed, a pipette was used to transfer the solution to a beaker of calcium chloride in order to produce hydrogel beads. |
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| The hydrogel beads were poured on to a mesh material. |
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| The labels designating the concentration amount of sodium alginate used to make a set of hydrogel beads were transferred to their appropriate partner beakers of calcium chloride and hydrogel beads. |
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| This is an overhead view of a beaker with calcium chloride and hydrogel beads. |
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| Each of the beakers that contained unique concentrations of sodium chloride with methylene blue (this solution in the form of many hydrogel beads) with calcium chloride were tested in the UV spectrometer to determine the rate of dye being released. |
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| Here's a picture of the group with our hydrogel beads! |
