Dr Rebeca Ruiz is the Principal Scientist at Pion Inc., who leads the design and execution of research experiments on the physicochemical properties of drugs and formulations, such as solubility, pKa, lipophilicity, dissolution, permeability, and absorption. Rebeca obtained the European Ph.D. in Analytical Chemistry from the University of Barcelona in Spain. Her thesis, and Master's were focused mainly on pKa (ionization constant) analysis, studying and evaluating a diversity of techniques and instrumentation (HPLC, CE, Spectrometers and Potentiometers), several media and different calculation approaches for the determination of this property. Lipophilicity (logP/D) and solubility also formed part of her doctorate and Rebeca publishes her work in internationally recognized scientific journals. Her expertise in physiochemical properties has been expanded over the years increasing her knowledge in dissolution, permeability, absorption, and the study of the effect by different families of excipients on the physicochemical properties including its role in formulations.