Drug Absorption By Jennifer Le, PharmD, MAS, BCPS-ID, FIDSA, FCCP, FCSHP, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego Reviewed / Revised Jun 2022 | Modified Sep 2022 View Patient Education Oral Administration Parenteral Administration Controlled-Release Forms Drug absorption is determined by the drug's physicochemical properties, formulation, and route of administration.