Please circle final answers for questions. Each question is worth 5 points.

1. Will a weak acid such as phenobarbital (pka = 7.2) have great difficulty crossing the biological membranes in the small intestine (pH 4 - 6)? (Yes or No) Why?

 

 

 

 

 

2. Calculate the half-life of a drug, when 32% of the dose remains in the body 8 hours after an i.v. bolus dose.

 

 

 

 

 

 

3. The data given in the table below are the plasma concentrations of ticarcillin as a function of time after i.v. bolus administration of 5.0 gram ticarcillin.

Plasma concentration of 5.0 gram iv ticarcillin dose

1. Prepare a semi logarithmic plot of plasma concentration versus time.
2. Estimate the half-life of ticarcillin.

 

3. Estimate the total clearance (Clp) of ticarcillin.