Accounts on the OBSSR e-Learning site enable you to save notes as you read the contents of the site.  Notes are a way for you to save a spot on the site with your own comments and title applied to it.  Think of it as putting a sticky note paper in a book to remember a place and leave a thought or two of your own for later reference.

Clinical Trials

3. Classification


For commercial purposes, trials have been classified into various phases, determined by the pharmaceutical industry based on the four phases of development of a particular drug (Phases I–IV) (Chow & Liu, 1998).

Figure 1

Figure 1 depicts the four phases of developing a pharmaceutical drug, the length of time each phase takes and number of volunteers per phase including; Animal/Laboratory studies (4 ½ years), Phase I (15-30 volunteers) Phase II (fewer than 100 volunteers) Phase III (100s to 1000s volunteers) total about 8 ½ years, FDA approval (1 ½ years) and Phase IV (after approval).

Show All

Phase I - Test Drug in Healthy Volunteers
Phase II - Test Drug in Patients with the Disease
Phase III - Test Drug Against Placebo or Standard Therapy
Phase IV - Test Drug While in the Marketplace
Chow SC, Liu JP. (1998). Design and analysis of clinical trials: Concept and methodologies. Chichester: John Wiley & Sons.