Paulo Paixão is an Assistant Professor of Pharmacokinetics and Biopharmaceutics at the Pharmacy Faculty of Lisbon University. Member of the PKWP at the EMA and national regulatory expert. Involved in the assessment of Bioequivalence and Clinical pharmacokinetics at the European and National level. Main topic of research activity has been related to Pharmacokinetics and Therapeutic Drug Monitoring. In particular QSAR, in vitro assays and data integration on PBPK models as well as other modelling and simulation approaches. His work have been mainly focusing in oral absorption with several papers with direct implication on present and future topics on bioavailability/bioequivalence regulatory establishment, namely on the establishment of pharmacokinetics metrics for bioequivalence of modified release formulations, and on the evaluation of similarity metrics for dissolution profiles. Later research interests are related to the better understanding of the physiology of the GI tract and its consequences in clinical variability for oral drug products.