Bioanalysis significance in Drug development

1. Bioanalysis in drug discovery and development
Dr. Manoj Ramesh Kumbhare
Professor and H.O.D.
(Pharmaceutical Chemistry)
Co-ordinator SMBT College of Pharmacy Dhamangaon Tal-Igatpuri
Dist. Nashik (M.S.) India
Mob-09850232594
mrkumbhare@rediffmail.com

2. Contents
What is bioanalysis ?
Overview of Drug discovery process
Preclinical development
Clinical development
manufacturing and sale
Combinatorial Chemistry
Automation High- throughput screening
Analytical Instrumentation – LC-MS
Drug discovery – Lead optimization
Screening in-vivo for pharmacokinetic properties
Screening in-vitro for pharmacokinetic properties
preclinical ADME and metabolite identification and characterization
Therapeutic drug monitoring

3. What is bioanalysis Bioanalysis
is a sub-discipline of analytical chemistry covering the quantitative measurement
of xenobiotics (drugs and their metabolites, and biological molecules in unnatural locations or
concentrations) and biotics (macromolecules, proteins, DNA, large molecule drugs,
metabolites) in biological systems.

4. Overview of Drug discovery process
The Drug Discovery Process involves many different stages and series of
actions. Typically, it can be divided into four main stages:
Early Drug Discovery, Pre-Clinical Phase, Clinical Phases, and Regulatory
Approval. Let's explore the major steps that are taken in each of these
stages to develop a new drug.

6. • In drug development, preclinical development, also
termed preclinical studies or nonclinical studies, is a stage of
research that begins before clinical trials (testing in humans) and
during which important feasibility, iterative testing and drug safety
data are collected, typically in laboratory animals.
• The main goals of preclinical studies are to determine a starting, safe
dose for first-in-human study and assess potential toxicity of the
product, which typically include new medical devices, prescription
drugs, and diagnostics.
• Companies use stylized statistics to illustrate the risks in preclinical
research, such as that on average, only one in every 5,000
compounds that enters drug discovery to the stage of preclinical

7. Clinical development
What is meant by clinical development?
Clinical Development, also called Drug Development, is a blanket term used to define the
entire process of bringing a new drug or device to the market. It includes drug discovery /
product development, pre-clinical research (microorganisms/animals) and clinical trials (on
humans).

8. Manufacturing Drugs
Drugs fall among the list of substances which must be delicately handled.
While it can be a life-saving remedy, it can also be a bane with inappropriate
usage. This prompts the need for a regulation, which in India can be found in
the Drugs and Cosmetics Act of 1940. This article explores the norms
pertaining to the manufacture, sale and distribution of drugs and cosmetics as
laid out in this Act.

9. Combinatorial chemistry involves the generation of a large array of structurally
diverse compounds, called a chemical library, through systematic, repetitive
and covalent linkage of various “building blocks”.
Combinatorial chemistry comprises chemical synthetic methods that make it possible to
prepare a large number (tens to thousands or even millions) of compounds in a single
process. These compound libraries can be made as mixtures, sets of individual compounds or
chemical structures generated by computer software. Combinatorial chemistry can be used
for the synthesis of small molecules and for peptides.
Strategies that allow identification of useful components of the libraries are also part of
combinatorial chemistry. The methods used in combinatorial chemistry are applied outside
chemistry, too.

10. What is High-Throughput Screening? Commonly used in drug discovery and other
life science fields, high-throughput screening (HTS) uses automated liquid
handling devices, multi-mode readers and other devices paired with data
processing and control software, to perform biological or chemical tests at
scale.
High throughput screening (HTS) is the use of automated equipment to rapidly test
thousands to millions of samples for biological activity at the model organism, cellular,
pathway, or molecular level.

11. Liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) is widely used for highly
selective and sensitive bioanalysis of small molecules. However, large molecule bioanalysis
presents challenges including the need for extensive and complex sample preparation for LC-MS-MS

12. Lead optimization is a critical process that culminates in the identification of a preclinical
candidate. The most promising hit series, once they are identified through hit-to-lead efforts,
advance into the lead optimization stage of drug discovery.

13. In Vitro and In Vivo Assessment of ADME and PK Properties During Lead Selection and Lead
Optimization
Assessment of the pharmacological properties of small molecule chemical compounds is critical
to the initial selection or identification of a chemical lead, and during the further lead
optimization to elucidate the Structure-Activity Relationships (SAR) and Structure Property
Relationships (SPR), and ultimately to select the compound(s) that will enter Investigational
New Drug (IND)-enabling studies. While extensive discussion of how Absorption, Distribution,
Metabolism, and Excretion (ADME) of compounds affects their ultimate pharmacokinetics (PK)
is beyond the scope of this chapter, herein, we provide guidelines for ADME and PK
assessments, benchmarks and practical “rules of thumb” for selecting compounds with sufficient
PK to be viable efficacious drugs.

14. Preclinical ADME and metabolite identification and characterization
Metabolite identification plays a critical role in the phases during drug development.
Drug metabolites can contribute to efficacy, toxicity, and drug-drug interaction. Thus,
the correct identification of metabolites is essential to understand the behavior of drugs
in humans. Drug administration authorities (e.g., FDA, EMA, and NMPA) emphasize
evaluating the safety of human metabolites with exposure higher than 10% of the total
drugrelated components. Many previous reviews have summarized the various
methods, tools, and strategies for the appropriate and comprehensive identification of
metabolites. We focus on summarizing the importance of identifying metabolites in the
preclinical and clinical phases of drug development. Summarized scenarios include the
role of metabolites in pharmacokinetics/pharmacodynamics (PK/PD) analysis,
disproportional exposure of metabolites that contribute to drug toxicity, changes in
metabolite exposure in renal-impaired patients, covalent tyrosine kinase inhibitors
(anticancer drugs), and metabolite identification of drug candidates from natural
medicines.

15. Therapeutic drug monitoring (TDM) is testing that measures the amount of certain medicines in
your blood. It is done to make sure the amount of medicine you are taking is both safe and
effective.
Therapeutic drug monitoring is useful only for drugs that have a poor correlation between dose and clinical
effect (high pharmacokinetic variability). Clearly, if dose alone is a good predictor of pharmacological effect,
then measuring the plasma concentration has little to contribute.

16. Conclusion
• In earlier days lack of suitable analysis of pharmacokinetic data due to lack of any high innovative
techniques bioanalysis.
• Bioanalysis emerges as an significant means throughout drug discovery and development.
• To support drug discovery programmes on the metabolic fate and pharmacokinetics of substances
• Bioanalysis deals with the quantitative evaluation of biological substances at unusual concentrations
are such as drug metabolites and Xenobiotics.
• The highest impact of bioanalysis measure of the drug or its metabolites for the study of
pharmacokinetics, toxicokinetics, bioequivalence and exposure-response like pharmacokinetic/
pharmacodynamic studies.
• Analyses in tissues and other fluids (urine, cerebrospinal fluid and bile) are also performed to help
understand the activity, toxicity or elimination of the drug.
• In addition to PK, large-molecule development requires immunogenicity testing (the property of a
large molecule to elicit an immune response in the patient), which has also become part of
bioanalysis, as it uses the same techniques as PK analysis.
• Finally, bioanalysis also comprises molecular biomarker assays, due to the similarity to PK in the
analytical approaches.