Principles of Drug Discovery

1. Guided by
Dr. A.D. Kulkarni
HOD of PQA
Prepared by
Mr. Vinayak R. Bodhankar
F.Y.M.PHARM (PQA)
Roll No. : 01
Sanjivani College of Pharmaceutical Education & Research,
Kopargaon

2.  Introduction to Drug discovery
 Discovery verses Invention
 Cost of Drug discovery and development
 Need of new drugs
 Steps in Drug discovery
 Clinical Research
 References

3. Discovery vs Invention

4.  Drug discovery is a process by which new
candidate medications are discovered.
 The process of drug discovery involves
identification of candidate, synthesis,
characterization, screening & assay for
therapeutic efficacy.
 Once a compound shows its value in these test,
the process of Drug development starts which
involves preclinical & clinical studies including
regulatory approval for commercialization of
New Chemical Entity

5. Synthesis of New Chemical Entity
IND to conduct Clinical trials
Completion of Phase – III trials
NDA to grant permission
Scrutiny of NDA
Launch the Drug in the Market

6.  The average time required to bring a New drug to the
market range from 12-15 years at an average cost of
$800 million.
 The innovator company synthesizes near about 5000-
7000 compounds out of which approximately 3-5
compounds reach to clinical level & out of which only
one comes to the market.
 Success rate is very low and it is estimated that only 3
out of 10 newly introduced drugs are able to recover
the R & D investment and can generate profit from it.

7. Fig. Approximate stepwise duration for Drug discovery and
development

8.  To combat the drug resistance
 For the improvement in the treatments of
existing diseases
 For the treatment of Newly identified
diseases
 Production of safer drugs by removal of
side effects

9.  Choose a disease
 Choose a Drug target
 Bioassay
 Find a Lead compound
 Isolate & purify lead compound
 Structural determination of lead compound
 Structural Activity Relationship
 Indentify Pharmacophore
 Improve target interaction

10.  Pharmacokinetic properties
 Design manufacturing process
 Clinical trials
 Patent the drug
 Launch the drug in a market

11. - Enzymes
- Receptors
- Nucleic acids, etc.

12.  It is an analytical method used to determine
concentration or potency of drug substance by it’s
effect on living cells or tissues.
 It is used to detect biological hazards.

13.  Compound that possess desired pharmacological
activity is called lead compound.

14. A) Natural sources :
Plants : Digitalis, morphine, etc.
Animals : Insulin, shark liver oil, etc.
Microorganisms : Penicillin, tetracycline, etc.
B) Synthetic banks
C) Existing drugs : It mainly includes “Me too drugs”
e.g of “Me too drugs”
Captopril Enalpril

15. D) Drug can also acts a lead compound based on its side
effects.
e.g Sulfanilamide --------- Tolbutamide
(Antibacterial) (Hypoglycemic agents)
Side effect : Hypoglycemia
E) Serendipity
 It is a chanced or accidental discovery.
 e.g Anti – impotence drug Vigra was discovered by chance
from a project aimed at developing a New heart drug.

16.  Purpose of isolation and purification of lead
compound is to separate the active constituent
from mixture and to get the active constituent
in 100% pure form.

17.  This can be done by using various analytical
techniques such as UV, IR, NMR, Mass
spectroscopy, etc.

18.  Objective of SAR is to determine part of drug
molecules which are important for biological
activity and which are not.
 X – ray crystallography and NMR can be used to
study and identify the interaction between drug
and active sites.
 In this way it is possible to find out which
groups are essential for biological activity and
which are not.

19.  It refers to study of location of functional
groups with respect to biological activity

23.  Manufactured drug need to fulfill the criteria of
clinical trials.
 This is necessary for safety purposes.

25.  Clinical research is a branch of healthcare science that
determines the safety and effectiveness of medications,
devices, diagnostic products and treatment regimen
intended for human use.
 Clinical research process includes :
 Preclinical testing
 IND
 Clinical studies : Phase – I, Phase – II, Phase – III
 Licensing and approval
 Post marketing studies

26.  It is study used to determine the pharmacological
profile of lead molecule using suitable animals.
 Many preclinical studies uses Review committee to
determine if the use of animals is warranted or not.
 Preclinical evaluation mainly consist of :
1) Toxicity study
2) Pharmacodynamic study
3) Pharmacokinetic study

27.  Upon satisfactory completion of preclinical studies, the
new compound is subjected to clinical studies through
proper application known as Investigational New Drug
Application to respective regulatory authorities
 In US : FDA
 In INDIA : DCGI
 For any IND protocol IRB approval is mandatory

28.  It consist of for different phases with specific objectives
 It Involves : Phase – I
Phase – II
Phase – III

29. Number of
participants
Length of
study
Drugs move
to the Next
phase
Objectives
Phase - I 20 - 100 06 – 09
month
70 % Determinatio
n of safe and
tolerable
dose
Phase – II 200 – 300 06 month to
2years
33% Determine
safety and
efficacy of
the drug
Phase - III 300 - 3000 1 to 4 years 25 – 30 % Monitor
adverse drug
reactions

30.  It is started once drug is marketed
 Also called as Post marketing surveillance
 It do not have specific period of time.
 It mainly focused on identification of rare side
effects, previously unknown side effects,
therapeutic indications, etc.

31.  https://www.fda.gov/forpatients/approvals/
drugs/ucm405382.htm
 http://www.drugdiscoverytoday.com
 Basic principles of Drug discovery and
Development by Benjamin E. Blass