Absorption of a drug by the cells requires that drug to be sufficiently non-polar to pass through the non-polar cell membrane. Therefore, the neutral molecules are absorbed more efficiently than the charged molecules by the cells of the human body.
Where will Ephedrine (Base, pKb = 4.4) be absorbed more effectively? (You can select one, two, or all)
Hint: Determine the dominant (most abundant) form, base/conjugate acid at each region of the intestine to determine if the molecule is charged or not.
a)Lower Stomach that has a pH = 2.0
b)Small Intestine that has a pH = 4.0
c)Large Intestine that has a pH = 6.0
d)None of the above