Pharmaceutical chemistry is a field of chemistry that studies organic chemistry (molecules and compounds) in conjunction with structural and chemical biology and pharmacology in order to develop pharmaceutical drugs and therapies. The design (drug design) and synthesis of physiologically active compounds is the focus of pharmaceutical (medicinal) chemistry. The goal is to obtain new chemical molecules that can be used to find new pharmaceuticals or to improve existing drug structures, hence expanding the chemical drug portfolio. The introduction of molecular biology changed pharmacokinetics (the study of how a drug and its metabolites behave in the body) and pharmacodynamics (the study of how a drug and its metabolites behave in the body). The development of computer techniques and approaches in molecular modelling approaches, as well as advances in analytical evaluation of new molecules, have all considerably broadened the reach and use of pharmaceutical chemistry, allowing for the development of a wider array of innovative drugs with new therapeutic potential.