controlled study nonhuman 90 IC 50 78 article 78 unclassified drug 78 Animals 68 priority journal 58 human 56 human cell 50 animal cell 46 Humans 42 in vitro study 42 Article 36 IC50 34 chemistry 28 drug effects 28 drug synthesis 26 mouse 26 drug cytotoxicity 24 metabolism 24 concentration response 22 drug structure 22 structure activity relation 22 Cell Line, Tumor 20 Cercopithecus aethiops 20 animal 20 animal experiment 20 drug screening 20 Antiviral Agents 18 Inhibitory Concentration 50 18