In Concept Check 15.6, we considered how to slow down the release of a drug in a transde...

In Concept Check 15.6, we considered how to slow down the release of a drug in a transdermal patch by increasing the thickness of the membrane. Which of the following strategies will decrease the rate at which drug molecules enter the body? (a) Lower the concentration of molecules in the patch. (b) Increase the temperature. (c) Use larger drug molecules.

(reference concept check 15.6)

The membrane in a transdermal patch (Fig. 15.13B) is typically about 200 mm thick. Suppose the thickness is doubled. How does that affect the rate with which the drug diffuses through the membrane?

(a) The rate is doubled.

(b) The rate is cut in half.

(c) The rate is reduced by a factor of four.