The scope and duration of these trials will vary widely, depending on the the nature of the drug and its therapeutic application. Industrial pharmacists are responsible for manufacturing and dispensing medicines for clinical trials. It is common to conduct clinical trials in several stages. I clinical trial gives valuable information about any adverse reactions and the fate of the drug in the healthy human body, these parameters may be different in patients suffering from the disease which the drug under test is designed to treat.
Penetration is poor in healthy individuals.
Phase II clinical trials are conducted on patients . Several hundred patients may take part and the trial may last from six months to two years. The primary aims of Phase II clinical trials are to establish clinical efficacy, determine the incidence of adverse reactions, define the optimum therapeutic dosage and provide detailed pharmacokinetic and pharmacological data to substantiate the adequate trial of the drug. In single blind trials , only the patients do not know whether they are receiving the drug or the placebo. In double blind trials , both the patient and the clinical investigators do not know which agent the patient is receiving - the pharmacist having made sure, when providing the samples, that the labelling code does not disclose this information.