I've read that pills should enter the epithelial cells of the intestinal lining to get into bloodstream. how exactly it penetrates the 'tight zones'?

Thought question: We take these for granted when advising patients. The pills themselves don't get in. The dissolve to their components and either go thru small pores, translocate via enzyme process and help or transport systems, or work on certain receptors in cells, exert their effect on these cells and allow the cells to perpetuate their intended activity through production of certain proteins by the cells.