[thewisegrow]

Hello, will someone help me interpret the protocol from a past clinical trial please? I took a screenshot of the publication & modified it for discussion purposes. I am only interested in Sample C at Day 16 which has a concentration of 24.0 mg/L. The protocol states, "For each dose, two portions of 500 mL each were administered at 4- hour intervals."

My question is how many mg of the active ingredient in Sample C did a participant consume within a 4- hour period? Also what was the total volume of fluid consumed during that 4- hour period?

I know if they take Sample C which has a concentration of 24.0 mg/L and they consume one 1 L dose of it then that means they would have consumed 24.0 mg of the active ingredient in Sample C. But it says each dose is two portions of 500 mL. I interpret this as they took Sample C which has a concentration of 24.0 mg/L and they consumed one 250 mL dose of it during a 2- hour period, and then they took Sample C again and they consumed another 250 mL dose of it during a second 2-hour period. My final answer is that 12.0 mg of the active ingredient in Sample C was consumed over a 4- hour period for a total of 500 mL of fluid consumed. Is this the correct way to interpret the protocol used? Thank you very much! Picture attached.

[penta-d]

It looks like this is either a very poorly written protocol or perhaps there is additional information (not shown?) that states explicitly what volume constitutes one dose. I can see how you might interpret it as 12.0 mg during a 4 hour period, but I don't think this is the only plausible interpretation given the wording. I don't see anything to suggest that 250 mL was given at 2 hour intervals. Clinical trial protocol writers go to great lengths to ensure that no interpretation is needed on the part of the reader. Is this type of problem really something being taught in high school chemistry?

[thewisegrow]

Hello, no this problem is not being taught in high school chemistry. I am not involved in high school chemistry. I am however interested in interpreting this protocol and thought that there might be a simple explanation for it which is why I posted it here. I have the original PDF and after reading your comment I went back to look harder at what it said. After re-reading the protocol I can see that the word portion is analogous to the word serving. Basically a 500 mL dose of a sample with a concentration of 24 mg/ L was administered during a 4- hour period and this was repeated one more time during that day. So that means a participant consumed a total of 24 mg of the active ingredient per day which had been mixed into one liter of fluid/water. Solved. Thank you for your time!