Displaying 9 results of Ritonavir Stable Isotopes Ritonavir is a protease inhibitor that is used in the treatment of HIV. Stable isotopes of ritonavir are isotopes that have the same number of protons and electrons, but a different number of neutrons. These isotopes are useful in research, as they allow scientists to track the metabolism and distribution of ritonavir in the body. Stable isotopes of ritonavir are also used in drug development, as they can help researchers better understand how the drug works and how it can be improved.