Clinical trial methodology
Preclinical Pharmacology and toxicology Biochemical and animal studies Phase I Basic human pharmacology Open/uncontrolled Phase II Efficacy in disease(s) Controlled trials/small randomised controlled trials Phase III Efficacy and comparative efficacy (for regulatory approval) Randomised controlled trials Phase IV Problems in clinical practice/ comparison with other drugs Observational studies/ randomised controlled trials Table 12.1 Phases of drug development and/or controlled, but these are rarely used in drug development studies; see the following text).