Pharmacy IV Math

by Amy
(FL)

If 10mL of a nitroglycerin injection (containing 5mg per mL) was used to make 1L of IV fluid, what is the w/v% strength of nitro in the finished product?

Comments for Pharmacy IV Math

Click here to add your comments

NTG percent problem
by: Brad Wojcik, Pharm D

You can either break this problem up into a couple of smaller problems or do it all in one step. The first step is always writing down the units of your answer. In this case it is a percent weight/volume, so the units of the answer will be % g/mL. (w=g, v=mL) The easiest way is to first calculate the amount of NTG in the 10 mL. 10 mL (5 mg/mL) = 50mg.
So, you are starting off with 50mg/1 L and you have to end up with the units of % g/mL. You have to change mg to g, L to mL and add the %. Changing the 1 L to mL, we are starting off with 50mg/1000 mL.
50 mg/1000 mL (1 g/ 1000 mg) (100%) = 0.005 % g/mL or 0.005% w/v. Remember, to add the %, just multiply by 100%. One step: 10 mL NTG soln/1 L (1 L/1000 mL) (5 mg NTG/ml NTG soln)(1 g/1000mg) (100%)= 0.005% g/mL or 0.005% w/v.
My answer
by: Anonymous

I got 0.05% w/v
Is that right? I don't know how you got 0.005% w/v.
Strength solution
by: Anonymous

%Strength = mg/mL x 100

10mL----> 5mg * 10 mL---> 50mg
1L---? 1000mL

% = 50/ 1000mL x 100


%S = 5%


Is that Right?

Click here to add your comments

Join in and ASK your Questions! It's easy to do. How? Simply click here to return to Math questions.

Popular Pages

More Info

Search