**2. Materials and Methods**

FCC was kindly provided by Omya International AG (Oftringen, Switzerland), and 1,2-dimyristoylsn-glycero-3-phosphocholine (DMPC) was a contribution of Lipoid GmbH (Ludwigshafen, Germany). Nifedipine and methanol were supplied by Sigma-Aldrich (subsidiary of Merck KGaA, Darmstadt, Germany). Acetonitrile and fuming HCl were bought from Carl Roth GmbH (Karlsruhe, Germany). Fasted state-simulated intestinal fluid powder and buffer concentrate were purchased from Biorelevant.com Ltd. (London, United Kingdom). The solvents were of high-performance liquid chromatography (HPLC) grade, and all other materials were of analytical grade.
