Science Buddies: "Ask an Expert"

I am thinking of doing my science fair project on dissolution time of analgesics, comparing brand and generic.....in my research I found a similar project. In this project simulated stomach acid was used to dissolve tablets. My quesitons is will the simulated stomach acid dissolve an enteric coated tablet and if it does, how do we know that the active ingredient in tablet was not degraded in such a way that it would be ineffective as an analgesic, I guess what I am asking - is this a true enough simulation??

Hi Whitney21,

I really like this project idea and it sounds like you've already done quite a bit of research. What are you using to simulate stomach acid? The wiki link below has a very detailed outline for simulating acid. If your design is similar to what they are describing, then I think your simulation will be fine for this project. Regarding the active ingredients in various tablets, it's likely that they will not be degraded by stomach acid (real or simulated). Medications that are swallowed (as opposed to injected) are designed to handle the acidic conditions of the stomach. If fact many drugs are not activated until they are broken down in the stomach.

http://www.wikihow.com/Simulate-Stomach-Acid

I hope this helps.

-Dave

Thank you for the link...............I will be testing the dissolution rate of brand and generic aspirin, acetaminaphen, and ibuprofen all of which have some type of enteric coating -- from my research, I have read that tablets are coated in this was to make it thru degradation of stomach acid to small intestine where most absorption takes place, dose this make any sense or am I reading to much into this -- should I just go for it?? Thanking you in advance!!!!!!!!!

Hi Whitney21,

You have clearly been doing your research and you have a good understanding of the information you have read.

It is true that the majority of digestion and absorption actually occur in the small intestine rather than the stomach (contrary to popular belief). Just to give you some insight into terminology, gastro- is a prefix used in reference to the stomach and entero- is a prefix used in reference to the small intestine. Thus, medicines with enteric coating are likely to resist the stomach acids so they can make it to the small intestine for efficient absorption.

What would be interesting is for you to test the dissolution rate of the medicines in simulated stomach acid (pH=1-2) and simulated fluid of the lumen (inside) of the small intestine (pH=6-7). Based on your research, I would hypothesize that you will find higher rates of dissolution in a fluid simulating that of the small intestine. You may need to dig a bit more into the research to find out how scientists simulate small intestinal fluid, but you may already have that answer.

Let us know if you have more questions...

Heather

Your project sounds like you are very educated in this subject. I am doing a similar project and I am having a hard time finding quality articles for my research, do you know of any good search engines, or possible articles?