Additionally, there are few comparisons of the pharmacokinetics of misoprostol between the buccal and vaginal routes. In fact, all of the PK studies comparing these routes are in women undergoing pregnancy terminations in the 1st or 2nd trimesters and do not include women undergoing labor induction at term. As the physiological changes in pregnancy have a profound impact on drug metabolism and disposition, this is an important gap in the current knowledge.