View Full Version : Please Help To Solve This!!!!!

06-26-2008, 09:56 PM
hi guys,

I was looking at the questions of the old blueprint and I found a couple of ones I am not sure about. Can you please help?

1 The half life of drug is 9 days. A single 0.5 mg dose of the drug yields and AUC value of 408 ng h/ml. In nanogram per milliliters what plasma level will result at steady state if this product is given once day and is 77% bioavailable?

2 the radioactive decay of radium has a rate constant of 4.22 x 10-4 per year. how many years will it take for 20% of the radium initially present to degrade? the amount initially present can be specified as 100%.

3 a solution initially contains methyl acetate 0.01M and NaOH 0.01 M. The solution is unbuffered and both reacting species are consumed. If the rate constant for this reaction at 25 C IS 1.082 L/molexmin, how many minutes will it take for the concentration of methyl acetate to fall to 0.0090 M?

Thanks guys in advance.


06-27-2008, 12:52 AM
Ans 1: I solved it like this. Please correct me if it is wrong

C = AUC/ T
C = 408/24
= 17

T = 1 day= 24 hour

06-27-2008, 03:48 AM
Hi Junee,

Thanks for your reply. I was wondering though, why they give 77% availability and Cp as well if we do not need to using them in the calculation.