Phase II in a clinical drug trial is

Ans. is 'b' i.e., Therapeutic exploration and dose ranging Summary of clinical tarilsPhaseNameConducted onBlinding and controlPurposeIHuman pharmacology and safetyHealthy volunteers (20-100)OPEN LABEL (No bliniding)* To know maximum tolerable dose (MTD).* Safety and tolerability.IITherapeutic exploratory100-150Patients (homogenous population)Single blindControlled* To establish therapeutic efficacy.* Dose ranging and ceiling effect.IIITherapeutic confirmatoryUpto 5000 patients from several centres (heterogenous population)Double blindRandomizedControlled* To confirm therapeutic efficacy.* To establish the value of drug in relation to existing therapy.IVPost marketing surveillanceLarge number of patients being treated by practicing physicians * To konwn rare and long-term adverse effects* Special groups like children, pregnancy etc can be tested.