PPIs are weak acids converted by CYP450 enzymes to the active form in parietal cells

Hmmm... This is not quite right now, is it? PPIs are weak bases and not weak acids. They are not activated by CYP450 enzymes in the stomach. Remember that CYP450 enzymes are primarily involved in drug metabolism in the liver and in the small intestine.

Please go back and re-consider.