Randomized controlled multicenter trials of drug:

Ans- C Phase 3 - randomized controlled multicenter trials REF: Goodman and Gillman's 11th edition page 82, http://en.wikipedia.org/wiki/Clinical_trial, s/ctphases.html CLINICAL TRIAL: Designation Study Population Sample size Phase 0 human microdosing studies pharmacodynamics and pharmacokinetics (no data on safety or efficacy, being by definition a subtherapeutic dose) Healthy volunteers 10 to 15 Phase 1 first stage of testing in human subjects safety (pharmacovigilance), dose-ranging tolerability, pharmacokinetics, and pharmacodynamics Healthy volunteers or individuals with target disease 20-100 Phase 2 efficacy (how well the drug works), dosing requirements (how much drug should be given), toxicity and continue Phase I safety assessments individuals with target disease 100-300 Phase 3 randomized controlled multicenter trials, "pre-marketing phase" how effective the drug is, in comparison ivith current gold standard' treatment (most expensive, time-consuming and difficult trials) individuals with target disease 300-3,000 or more Phase 4 Postmarketing surveillance Trial safety surveillance (pharmacovigilance, designed to detect any rare or long-term adverse effects) individuals with target disease as well as new age groups, genders, etc. Thousands