Drug discovery

Introduction:
Drug discovery is the research process of designing and discovering a new drug for the required biological responses in animals resulting in desired effects in human beings. The process of drug discovery is done in different fields like Pharmacology, Biotechnology and medicine.

In old times, drug was discovered either
1. checking the ingredients from conventional or known remedies or
2. by accidental discoveries

But now study is done even the minutest molecular and physiological level so that the better drugs, targeting the specific receptors, are developed. Drug discovery is one the most lengthy and expensive processes in Pharmaceutical and related fields. One of the most important process for Drug discovery is High-Throughput screening.

Stages for an approved new molecular entity:
A new molecular entity passes through the following stages:
1. Drug Discovery
    a. Identification
    b. Synthesis
    c. Characterization
    d. Screening
    e. Assays for therapeutic effectiveness
2. Drug Development or Preclinical Development
3. Clinical Trials
    a. Phase 0
    b. Phase 1
    c. Phase 2
    d. Phase 3
    e. Phase 4

Challenges to Overcome in Drug Discovery:

Following changes are usually considered in Drug Discovery:
1. Effective targeting of the drug
2. Drug must be cost effective
3. Patient Compliance
4. Prevention of drug from degradation
5. Extended life of the drug product

Drawbacks in Drug Discovery and its removal:
This process is
- lengthy,
- difficult,
- expensive and
- Inefficient having low rate of new drug discovery.

Nowadays, the knowledge of human genome has very benefacial effects on the drug discovery as it has removed many steps of drug discovery including the study of new drug targets.