Prepared By Pawan Dhamala RR College Of Pharmacy Chikkabanavara , Bangalore , 560090

1. STAGES OF DRUG DISCOVERY
PAWAN DHAMALA
B.PHARMACY 8TH SEMESTER
RR COLLEGE OF PHARMACY,BANGALORE

2. DRUG DISCOVERY
1)Drug discovery is a process
of identifying a compound therapeutically
useful in remedial and treating diseases.
2) Drug discovery involves identification,
synthesis,characterization,screening and
assay for therapeutic efficacy.

3. STAGES OF DRUG DISCOVERY
1.Target Identification
2.Target Validation
3.Lead Identification
4.Lead optimization
5.Pre-clinical Safety
6.Clinical Trials

4. Target Identification
➢ Target Identification is the first and key step in drug discovery channel.
➢ A drug target is the specific bindingsite for a drug in vivo through which it exerts
action.
➢ Usually, drug target refers to a single biomolecule.
A specific drug target has following characteristics;
1. The drugtarget can be a biomolecule i.e; protein
2. The biomolecule have a special sites or locations.
3. The biomolecule structure may change when it binds to drugs.
4. With the change in the biomolecule structure various physiological response
occurs.
5. Physiological response play a major role in regulation of complex function of
cells that exerts a therapeutic effects.
6. Structure of biomolecule may change over the duration of the pathological
condition.

5. Limitations of Drug Target;
1. It would not be equally effective in the treatment of the disease.
2. Drug target needs an understanding of the pathogenesis of the disease.
3. Drug and target relation is not one to one but one to many.
4. It may distrupt the body's homeostasis.
Target validation
Target validation helps to new drug researchand development and provide
more views on pathogenesis of target-related disease.
The validation process includes;
❖ Discovery of the biomolecule of interest.
❖ Evaluation of its potential as a target.
❖ Designing a bioassay to measure its biological activity.
❖ Constructinga high-throughput screening method.
❖ Performingscreeningto find hits.
❖ Evaluation of hits.

6. Lead discovery
➢Compounds that are synthetic chemicals,peptides,naturalor
engineered proteins, or antibodies are exposedto the target in a
manner that will detect and identify those compound in the library
that interact with target.The compound selectedare called leads.
➢Leads can be obtainedby molecular modelingwith thehelpof
computer graphics.
➢A combinational chemistry can alsoattemptedto get lead.This
technique generates billions of compound.If any compoundshow a
positive response,traditional laboratory methods are usedto
manufacture themat a large scale.
➢Usingbiotechnology proteins as drugs,the use of recombinant DNA
technology/geneticengineering to clone and express humangenes
is another methodusedto obtain leads.

7. Lead optimization
➢Lead optimization is the process that begins with a compoundthat
shows a potential biological action and confirms with the
identification of thebest compound.
➢Molecules are chemically modified andcharacterized to make a
compound with desiredproperties to become a drug.
➢Leads are optimized for efficacy and potency in vitroand in vivo,
physiochemical properties,pharmacokinetic properties,and
toxicologicalaspects.
➢Although this stage is a major hurdle in drug discovery it contributes
to turninga biologically activechemical intoan effectiveand safe
drugin the drug discovery process.

8. Pre-clinical safety
➢It includes developinga methodof large-scale synthesis, animal
safety studies,carcinogenicity tests,drugdelivery elimination and
metabolismstudies,drugformulation experiments,and dose-
rangingstudies in animals.
Clinical trials
The National Institutes of Health (NIH) organizes clinical trials into5
different types:
1. Treatment trials: This trial test the new combination of drugs.
2. Prevention trials: This trial search for a way to prevent a disease or
prevent it from recurring.
3. Diagnostic trials: This trial finds better tests or procedure for
diagnosing a disease.

9. 4. Screening trials: This trial tests methods of
detecting disease.
5. Quality of life trial: This trial explore ways to
improve comfort and quality of life for individual
with a chronic illness.