Development and validation of HPLC-DAD and LC-(ESI)/MS methods for the determination of sulfasalazine, mesalazine and hydrocortisone 21-acetate in tablets and rectal suppositories: In vitro and ex vivo permeability studies

Vasileios Tsamis, Eleni Tsanaktsidou, Christina Karavasili, Constantinos K. Zacharis, Nikolaos Bouropoulos, Dimitrios G. Fatouros, Catherine K. Markopoulou