process for discovery and development of new drug and issues related to testing of drug on human
1. The process/stages for discovery
and development of new
drug/vaccines and social,
economical and legal issues
related to testing of new drug on
human volunteers.
Made By-Teena
Roll No- 5
Msc Biotechnology Final Year
Submitted to-Dr. Sulekha Rani
2. PHASES OF DRUG
DEVELOPMENT
There are three major phases in drug
development:
1. Pre-clinical research and development
2. Clinical research and development
3. After the compound is on the market, a
possible “post-marketing” phase
3. The pre-clinical phase represents bench (in
vitro) and then animal testing, including
kinetics, toxicity and carcinogenicity. An
investigational new drug application is
submitted to the FDA seeking permission to
begin the heavily regulated process of clinical
testing in human subjects.
The clinical research phase—representing the
time from beginning of human trials to the new
drug application submission that seeks
permission to market the drug—is by far the
longest portion of the drug development cycle
and can last from 2 to 10 years.
4. Stages of Drug Development
➢Drug Invention
➢Product Characterization
➢Formulation& development
➢Pharmacokinetics And Drug Disposition
➢Preclinical Toxicology Testing And IND
Application
➢Bioanalytical Testing
➢Clinical Trials
➢Regulatory review
➢Marketing the product or drug
➢Post-marketing monitoring (phase-IV)
trials
6. Discovery
Discovery often begins with target identification –
choosing a biochemical mechanism involved in a disease
condition.
Drug candidates, discovered in academic and
pharmaceutical/biotech research labs, are tested for their
interaction with the drug target.
Up to 5,000 to 10,000 molecules for each potential drug
candidate are subjected to a rigorous screening process
which can include functional genomics and/or proteomics
as well as other screening methods.
Once scientists confirm interaction with the drug target,
they typically validate that target by checking for activity
versus the disease condition for which the drug is being
developed.
After careful review, one or more lead compounds are
chosen.
9. Product Characterization
When the candidate molecule shows
promise as a therapeutic, it must be
characterized—the molecule’s size, shape,
strengths and weaknesses, preferred
conditions for maintaining function, toxicity,
bioactivity, and bioavailability must be
determined. Characterization studies will
undergo analytical method development
and validation. Early stage pharmacology
studies help to characterize the underlying
mechanism of action of the compound.
10. Formulation, Delivery, Packaging
Development
Drug developers must devise a formulation that ensures the
proper drug delivery parameters. It is critical to begin looking
ahead to clinical trials at this phase of the drug development
process. Drug formulation and delivery may be refined
continuously until, and even after, the drug’s final approval.
Scientists determine the drug’s stability—in the formulation
itself, and for all the parameters involved with storage and
shipment, such as heat, light, and time. The formulation must
remain potent and sterile; and it must also remain safe
(nontoxic). It may also be necessary to perform leachables
and extractables studies on containers or packaging.
11. Pharmacokinetics And Drug
Disposition
Pharmacokinetic (PK) and ADME
(Absorption/Distribution/Metabolism/Excretion)
studies provide useful feedback for formulation
scientists. PK studies yield parameters such as
AUC (area under the curve), Cmax (maximum
concentration of the drug in blood), and Tmax
(time at which Cmax is reached). Later on, this
data from animal PK studies is compared to
data from early stage clinical trials to check the
predictive power of animal models.
12. Preclinical Toxicology Testing and
IND Application
Preclinical testing analyzes the
bioactivity, safety, and efficacy of the
formulated drug product. This testing is
critical to a drug’s eventual success and,
as such, is scrutinized by many
regulatory entities. During the preclinical
stage of the development process, plans
for clinical trials and an Investigative
New Drug (IND) application are
prepared. Studies taking place during
the preclinical stage should be designed
13. The main stages of testing are:
Acute Studies
Acute tox studies look at the effects of one or more doses
administered over a period of up to 24 hours. The goal is to
determine toxic dose levels and observe clinical indications of
toxicity. Usually, at least two mammalian species are tested.
Data from acute tox studies helps determine doses for repeated
dose studies in animals and Phase I studies in humans.
Repeated Dose Studies
Depending on the duration of the studies, repeated dose studies
may be referred to as subacute, subchronic, or chronic. The
specific duration should anticipate the length of the clinical trial
that will be conducted on the new drug. Again, two species are
typically required.
14. Genetic Toxicity Studies
These studies assess the likelihood that the drug compound is
mutagenic or carcinogenic. Procedures such as the Ames test
(conducted in bacteria) detect genetic changes. DNA damage is
assessed in tests using mammalian cells such as the Mouse
Micronucleus Test. The Chromosomal Aberration Test and similar
procedures detect damage at the chromosomal level.
Reproductive Toxicity Studies
Segment I reproductive tox studies look at the effects of the drug
on fertility. Segment II and III studies detect effects on embryonic
and post-natal development. In general, reproductive tox studies
must be completed before a drug can be administered to women
of child-bearing age.
Carcinogenicity Studies
Carcinogenicity studies are usually needed only for
drugs intended for chronic or recurring conditions. They
are time consuming and expensive, and must be
planned for early in the preclinical testing process.
15. Bioanalytical Testing
Bioanalytical laboratory work and bioanalytical method
development supports most of the other activities in the drug
development process. The bioanalytical work is key to proper
characterization of the molecule, assay development,
developing optimal methods for cell culture or fermentation,
determining process yields, and providing quality assurance
and quality control for the entire development process. It is
also critical for supporting preclinical toxicology/pharmacology
testing and clinical trials.
Clinical Trials
Clinical studies are grouped according to
their objective into three types or phases:
16. Phase I Clinical Development (Human Pharmacology)
Thirty days after a biopharmaceutical company has filed its IND, it may
begin a small-scale Phase I clinical trial unless the FDA places a hold on
the study. Phase I studies are used to evaluate pharmacokinetic
parameters and tolerance, generally in healthy volunteers. These studies
include initial single-dose studies, dose escalation and short-term
repeated-dose studies.
Phase II Clinical Development (Therapeutic Exploratory)
Phase II clinical studies are small-scale trials to evaluate a drug’s
preliminary efficacy and side-effect profile in 100 to 250
patients. Additional safety and clinical pharmacology studies are also
included in this category.
Phase III Clinical Development (Therapeutic
Confirmatory)
Phase III studies are large-scale clinical trials for safety and efficacy in
large patient populations. While phase III studies are in progress,
preparations are made for submitting the Biologics License Application
(BLA) or the New Drug Application (NDA). BLAs are currently reviewed
by the FDA’s Center for Biologics Evaluation and Research
(CBER). NDAs are reviewed by the Center for Drug Evaluation and
17. Clinical trials form an integral part of the drug discovery process
worldwide. Clinical trials are the set of practices required to certify a new
drug molecule as safe and efficacious for the market. Medical research,
in general, is a good thing and absolutely necessary to cure number of
chronic diseases.
At present in India we have 40 million asthmatic patients, about 34
million diabetic patients, 8-10 million people with HIV, 8 million epileptic
patients, 3 million cancer patients, more than 2 million cardiac-related
deaths, 1.5 million people with Alzheimer's disease; 15% of the
population is hypertensive, and 1% suffers from schizophrenia1 In order
to give best treatment to above diseases research on humans is both
necessary and desirable. A clinical trial is defined as "any research study
that prospectively assigns human participants or groups of humans to
one or more health-related interventions to evaluate the effects on health
outcomes2." Interventions include not only drugs but also cells and other
biological products, surgical procedures, radiologic procedures, devices,
behavioral treatments, process-of-care changes, preventive care, etc.
18. GENERAL ETHICAL PRINCIPLE
All research involving human subjects should be conducted in
accordance with three basic ethical principles, namely respect for
person, beneficence and justice. The present guidelines are directed at
the application of these principles to research involving human subjects
. (A) RESPECT FOR PERSONS
includes at least two fundamental ethical considerations, namely
1. Respect for autonomy It includes the idea that an individual is free to
choose and to act. Both rational capacity and freedom from constraint
are necessary elements. “Respect for persons” includes respecting the
decisions of autonomous beings. 2. Protection for those with impaired or
diminished autonomy It means a recognition by the commission that
these people are not capable of self determination at all times and in all
circumstances.
(B) BENEFICENCE –
includes the ethical obligation to maximize benefits and minimize harms
and wrongs.
(C) JUSTICE –
In the ethics of research involving human subjects the principle primarily
refers to distributive justice, which means equitable distribution of both
burden and the benefits of participation in research.
19. TWELVE BASIC PRINCIPLES
1 Principle of Essentiality.
2.Principle of voluntariness and Informed
Consent.
3.Principle of Non-exploitation.
4 Principle of Privacy and Confidentiality
5 Principle of Precautions and Risks
Minimisation
6 Principle of Professional Competence
7 Principle of Accountability and Transparency.
8.Principle of Maximisation of Public Interest and
of Distributive Justice.
9 Principle of Institutional Arrangements.
10 Principle of Public Domain.
11 Principle of Totality and Responsibility.
21. If all these principles are
not followed then
social,economical and
legal issues may arise
during a trial on human
volunteer
23. REFRENCES
1. Strovel, Jeffrey; Sittampalam, Sitta; Coussens,
Nathan P.; Hughes, Michael; Inglese, James; Kurtz,
Andrew; Andalibi, Ali; Patton, Lavonne; Austin, Chris;
Baltezor, Michael; Beckloff, Michael; Weingarten,
Michael; Weir, Scott (July 1, 2016). "Early Drug
Discovery and Development Guidelines: For Academic
Researchers, Collaborators, and Start-up
Companies Assay Guidance Manual. Eli Lilly &
Company and the National Center for Advancing
Translational Sciences.
2. Taylor, David (2015).The Pharmaceutical Industry and
the Future of Drug Development. Issues in
Environmental Science and Technology. Royal Society
of Chemistry