Clinical trials are research studies that discover whether a medical treatment, strategy, or device is effective and safe for humans. There are four stages of clinical trials: phase Ι, phase ΙΙ, phase ΙΙΙ, and phase ΙV. Identification of pharmacological actions and tolerability is done in phase I. Phase ΙΙ evaluates drug safety and efficacy. Phase III involves the evaluation of risk benefit ratio and determination of dosage interval. 更多
