Drug Discovery & Drug Development

Question 1

Sources of Drugs

Answer 1

Drugs from plants source - Cardiac glycosides
Drugs from animal source - Insulin, thyroxin, pepsin
Drugs from mineral source - Iron, zinc, mercury
Drugs from micro-organisms - Antibiotic (penicilin, streptomycin)
Semi-synthesis - Homatropine
Synthesis - Chloroquine, acetylsalicyclic acid

Question 2

Preclinical Trails

Answer 2

Conducted in animals to access primary safety & activity

To determine new drugs ultimate safety profile

• Pharmacokinetics
• Pharmacodynamics
• Toxicity studies

Question 3

What tests in preclinical trails?

Answer 3

Acute, subacute and chronic toxicity are tested in various animals.

General screening test on,

• Pharmacologic effects
• Reproductive toxicity
• Carcinogenicity

Question 4

Clinical trials

Answer 4

Phase I - 25 to 30 to establish limits of safe clinical dosage range

Phase II - 100 to 300 to determine efficacy , safety and optimum dose

Phase III - 1000 to 5000 to detect infrequent toxicities

Phase IV - post marketing surveillance phase