Hi everyone,
This week, I set up and ran a drug release study. The goal of a drug release study is to measure the amount of drug released from a gel after a particular duration of time.
To set up the release study, I first mix the gels with a drug solution as described in last week’s blog post. After the gels are mixed, I squeezed approximately 200 milligrams from the syringe into a labeled vial. For each acid/salt used (sodium chloride, sodium sulfate, hydrochloric acid, sulfuric acid) and for each concentration of acid/salt used (0, .2 millimol, .35 millimol), I created three gels. In total, I had twenty-seven vials. After the gels are placed into the vials, they are covered by a solvent and set in a warm room, or a room that is kept around 37C.
Once the study is set up, the next crucial component is taking time points. In this lab, time points are times when some solvent is taken from each vial and placed into a tube that is labeled for the time and for the vial whose content it contains. The rest of the solvent from the vial is thrown out, and then new solvent is added to the vial. This week, I took time points at one hour (after set up), three hours, twenty-four hours, forty-eight hours, and ninety-six hours.
After the time points are taken, a test to determine how much drug was released at each time point can be performed. This is done by taking a small amount of each solvent from the tubes and placing it into an ultraviolet transparent plate (see first picture below). Then the plate is placed into a spectrometer (see second picture below) that sends a particular light through each well and records the absorbance. In addition to placing the solvent/drug solutions onto the plate, a group of standards is created and placed onto the plate. Standards are solutions in which the concentration of drug is known. This is important for calculating the amount of drug because it is from the standard solutions that a linear relationship can be made between the absorbance and the concentration of drug.
Over the past week, I performed all three of those steps. Now, I have to process the data from the spectrometer and examine how the drug was released. Hopefully, I can get this done soon and present it in this blog.
Russell Llave
Seems like things are going more smoothly in the lab this week. You have accomplished quite a bit! Is the spectrometer much more sophisticated than the one we have at BASIS? I look forward to reading about your results next week!
ReplyDeleteThe idea behind the spectrometer is very similar, but rather than using one tube (like the one at BASIS), the one at lab can read multiple samples as long as they are on a specific plate.
DeleteLooks like you've made a lot of progress this week. I'm excited to see the results from the spectrometer whenever you finish processing it.
ReplyDeleteMan, do I remember the days of spectroscopy from AP Chem. Good times. Speaking of which, do you know what factors from your set up could be potential sources of error?
ReplyDeleteKeep up the great lab work Russell!