Pharmacology Activity: Drug Testing

20 Feb

Back in October I ran some workshops relating to careers in Bio-Sciences. Each activity we did related to a particular degree programme and this one was all about Pharmacology.

MP900337294As I’m sure you can appreciate I didn’t want to test any drugs that could be deemed even vaguely dangerous…imagine the risk assessments *shudder*. So, to maintain a balance between real world applications and safety we tested the effectiveness of some ‘new compounds’ that a drugs company were thinking of introducing into the market to treat heartburn. These new drug candidates were in fact Boots bog standard antacids mixed with varying amounts of Trebor XXXX mints.

CIMG1569

After discussing stomach acid, heartburn and how antacids worked the students had to test out the drug candidates. Once the students had tested the drug candidates’ effectiveness they had to make a recommendation as to which one a pharmaceutical company should use in their new antacid drug.

If you want to do this activity you will need:

  • Antacids.
  • Chalky mints.CIMG1566
  • Something to crush the above. I used a pestle and mortar. Now anything else I try to crush in it tastes minty.
  • Around 0.5-1ml of Aspall White Wine vinegar per test – it’s a really dilute, weak acid so works very well and much more reproducible than making up dilute acid in different schools.
  • Something to put the 1ml of vinegar in (I used eppendorf tubes), preferably with a lid so it can be inverted with solution in.
  • pH indicator strips – must be pH scale not litmus paper (we used some Whatman ones my supervisor let me swipe from lab). The change in pH isn’t dramatic enough to be detected by litmus paper as the tablets are just a buffer and won’t turn the solution into an alkali. I think you could use pH indicator solution as well if the students only add a tiny drop, but using the strips is quite fun.
  • A worksheet the students can write the pH of the acid before and after the addition of drug and jot down the recommendations to the drug company on which compound to use in their antacid.
Eppendorf Tube

Eppendorf Tube

Step 1. (Prep) Crush the antacids and mints. Make three mixes: 1) Equal mix of antacid and mints 2) Just mints and 3) Just antacids. Pre-measure them (although you could get the students to do this – we were short on time) and separate them into labelled tubes. We gave each group 3 eppendorf tubes about a quarter full of containing one of each mix.

Step 2. (Prep) Pre-measure out the vinegar into whatever you’re using to hold it , we used eppendorfs*. Each group will need 3 tubes of vinegar.

Step 3. The students need to measure the pH of the ‘acid’ before. They only need to do this with one.

Step 4. Tip the drug candidates into the acid and invert several times.

Step 5. Measure the pH after addition of drug candidates and based on their findings students can write their recommendation to the Pharmaceutical company as to which compound is most effective.

The only word of caution I would give in this practical is the vinegar is pretty pongy. Also, the mints quite clearly smell like mints so if anyone has suggestions for something else to use it would be greatly appreciated!

*If you choose to use eppendorfs like us, consider piercing a hole in the top and telling the students to protect their fingers with a piece of blue roll/tissue when inverting the tube.  We didn’t do this on the first session and I’d forgotten that mixing acid with a carbonate base will produce H2O and CO2 (D’Oh! Basic Chemistry). The CO2 causes pressure build up and the eppendorf pops open (for the Biologists reading this – the same way they pop when you over boil gel samples). This was actually fine – the teacher found it funny and the students loved it, plus we talked about the reaction and pressure but it isn’t actually relevant for this practical. If you wanted to demonstrate how the gas is produced in this reaction for a chemistry practical however, this would work really well!

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: