Stages of drug discovery and development MCQs With Answer

Introduction: The stages of drug discovery and development encompass target identification, hit discovery, lead optimization, preclinical studies, clinical trials (Phase I–IV), regulatory submission, and post-marketing surveillance. For B. Pharm students, understanding techniques such as high-throughput screening, structure-based design, ADME/Tox evaluation, pharmacokinetics/pharmacodynamics, and IND/NDA preparation is essential. This topic highlights how medicinal chemistry, in vitro and in vivo models, GLP/GMP standards, and regulatory strategy converge to translate a molecule into an approved medicine. Mastery of these stages improves your ability to evaluate drug candidates, design experiments, and interpret safety and efficacy data. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which stage primarily focuses on identifying a biological target and validating its role in disease?

• Hit-to-lead optimization
• Target identification and validation
• Preclinical toxicology testing
• Phase II clinical trials

Correct Answer: Target identification and validation

Q2. What is the main purpose of high-throughput screening (HTS) in early drug discovery?

• Assessing long-term safety in humans
• Rapidly testing large chemical libraries to find active ‘hits’
• Manufacturing scale-up of lead compounds
• Conducting randomized controlled clinical trials

Correct Answer: Rapidly testing large chemical libraries to find active ‘hits’

Q3. During hit-to-lead and lead optimization, which concept evaluates how structural changes affect biological activity?

• Chemical equivalence
• Structure-Activity Relationship (SAR)
• Good Laboratory Practice (GLP)
• Bioequivalence

Correct Answer: Structure-Activity Relationship (SAR)

Q4. Which preclinical study assesses absorption, distribution, metabolism, and excretion properties?

• Safety pharmacology
• ADME studies
• Phase I clinical trial
• Pharmacovigilance

Correct Answer: ADME studies

Q5. What does NOAEL stand for and why is it important in preclinical toxicology?

• No Observable Adverse Effect Level; used to estimate safe starting doses for humans
• New Observable Activity Evaluation Limit; used in HTS hit selection
• Number of Animals Evaluated for Lethality; used in acute toxicity only
• Neutral Optimization and Analytical Evaluation Level; used in formulation

Correct Answer: No Observable Adverse Effect Level; used to estimate safe starting doses for humans

Q6. What regulatory application must be submitted to begin clinical trials in humans in many countries?

• Abbreviated New Drug Application (ANDA)
• Investigational New Drug (IND) application
• Certificate of Pharmaceutical Product (CPP)
• Biologics License Application (BLA)

Correct Answer: Investigational New Drug (IND) application

Q7. Phase I clinical trials primarily evaluate which of the following?

• Long-term efficacy versus standard of care
• Safety, tolerability, and pharmacokinetics in healthy volunteers or patients
• Post-marketing adverse event reporting
• Large-scale manufacturing consistency

Correct Answer: Safety, tolerability, and pharmacokinetics in healthy volunteers or patients

Q8. Which phase of clinical trials focuses on proof of concept and preliminary efficacy in patients?

• Phase II
• Phase IV
• Phase I
• Preclinical

Correct Answer: Phase II

Q9. What is the primary objective of Phase III clinical trials?

• To demonstrate safety and efficacy in large patient populations for regulatory approval
• To perform initial ADME screening in vitro
• To identify molecular targets using genomics
• To perform cost-analysis for commercialization

Correct Answer: To demonstrate safety and efficacy in large patient populations for regulatory approval

Q10. Which document compiles quality, safety, and efficacy data for marketing authorization (e.g., NDA)?

• Investigator’s Brochure
• New Drug Application (NDA) or Marketing Authorization Application (MAA)
• Informed consent form
• Preclinical study protocol

Correct Answer: New Drug Application (NDA) or Marketing Authorization Application (MAA)

Q11. What does IND-enabling toxicology typically include?

• Phase IV pharmacovigilance studies
• GLP-compliant acute, subchronic toxicity, genotoxicity, and safety pharmacology studies
• Bioequivalence testing only
• Clinical endpoint selection

Correct Answer: GLP-compliant acute, subchronic toxicity, genotoxicity, and safety pharmacology studies

Q12. Which parameter describes the relationship between drug dose and blood concentration over time?

• Pharmacodynamics (PD)
• Pharmacokinetics (PK)
• Biopharmaceutics classification
• Structure-activity relationship

Correct Answer: Pharmacokinetics (PK)

Q13. What is the meaning of MABEL and its use in first-in-human dose selection?

• Maximum Absorbed Bioavailability Elevated Level; used for formulation
• Minimum Anticipated Biological Effect Level; used to estimate a safe starting dose based on pharmacology
• Maximum Allowed Bioequivalence Limit; used in generic approvals
• Median Animal Bioactivity Estimate Level; used for animal model selection

Correct Answer: Minimum Anticipated Biological Effect Level; used to estimate a safe starting dose based on pharmacology

Q14. Which in vitro assay is commonly used to predict cytochrome P450-mediated metabolism?

• hERG potassium channel assay
• Microsomal stability or recombinant CYP enzyme assay
• Large animal toxicology
• Phase III clinical trial

Correct Answer: Microsomal stability or recombinant CYP enzyme assay

Q15. What is the role of formulation development during drug development?

• To validate biological targets using genomics
• To design a manufacturable dosage form that optimizes stability, bioavailability, and patient compliance
• To perform randomized, double-blind placebo-controlled trials
• To conduct GLP toxicology only

Correct Answer: To design a manufacturable dosage form that optimizes stability, bioavailability, and patient compliance

Q16. Which safety test focuses on potential effects of a drug on the cardiac hERG channel and QT interval?

• Genotoxicity assay
• hERG assay / cardiac safety pharmacology
• In vivo carcinogenicity study only
• Bioequivalence study

Correct Answer: hERG assay / cardiac safety pharmacology

Q17. What is a biomarker and how is it used in drug development?

• A chemical excipient; used to stabilize formulations
• A measurable indicator of biological or pathogenic processes; used for diagnosis, patient selection, or measuring drug effect
• A regulatory filing code; used in IND submission
• A statistical tool only used in Phase IV

Correct Answer: A measurable indicator of biological or pathogenic processes; used for diagnosis, patient selection, or measuring drug effect

Q18. Which study assesses long-term carcinogenic potential of a drug candidate?

• Acute toxicity study
• Chronic carcinogenicity study in rodents and non-rodents
• Phase I clinical pharmacology study
• Stability under accelerated conditions

Correct Answer: Chronic carcinogenicity study in rodents and non-rodents

Q19. What is the importance of CMC (Chemistry, Manufacturing, and Controls) in regulatory submissions?

• It defines clinical trial endpoints only
• It provides detailed information on drug substance and product quality, manufacturing process, and control tests required for approval
• It is only relevant for biological drugs
• It describes patient recruitment strategies

Correct Answer: It provides detailed information on drug substance and product quality, manufacturing process, and control tests required for approval

Q20. Which term describes a drug’s overall safety margin comparing toxic dose to therapeutic dose?

• Therapeutic index
• Bioavailability
• Pharmacodynamic potency
• Drug-likeness

Correct Answer: Therapeutic index

Q21. What is the primary focus of Phase IV (post-marketing) studies?

• Initial human safety and PK
• Monitoring long-term safety, rare adverse events, and additional indications
• Hit identification from chemical libraries
• Optimizing lead compound potency only

Correct Answer: Monitoring long-term safety, rare adverse events, and additional indications

Q22. Which concept involves using computational methods to predict binding of small molecules to targets?

• Physicochemical profiling
• Structure-based drug design / molecular docking
• In vivo toxicokinetics
• Good Manufacturing Practice

Correct Answer: Structure-based drug design / molecular docking

Q23. For biosimilars or generics, which regulatory study demonstrates therapeutic equivalence to the reference product?

• Carcinogenicity testing
• Bioequivalence studies
• Phase II dose-ranging trials
• GLP safety pharmacology only

Correct Answer: Bioequivalence studies

Q24. What role does pharmacovigilance play after drug approval?

• Designing preclinical assays
• Systematic collection, analysis, and prevention of adverse drug reactions in real-world use
• Selecting leads from HTS
• Optimizing chemical synthesis routes

Correct Answer: Systematic collection, analysis, and prevention of adverse drug reactions in real-world use

Q25. Which assay is used to assess potential genotoxicity of a new chemical entity?

• Ames test and in vitro micronucleus assay
• hERG assay only
• Bioavailability study
• Phase III randomized trial

Correct Answer: Ames test and in vitro micronucleus assay

Q26. What is ‘lead-like’ or ‘drug-like’ property assessment often guided by Lipinski’s Rule of Five?

• Guidelines for clinical trial design
• Physicochemical criteria predicting oral bioavailability
• Standards for GLP documentation
• Regulatory labeling format

Correct Answer: Physicochemical criteria predicting oral bioavailability

Q27. Which animal model consideration is crucial for translational relevance?

• Cost of animals only
• Phylogenetic distance, similarity of disease mechanism, and PK/PD translatability
• Manufacturer location
• Availability of high-throughput screening in that species

Correct Answer: Phylogenetic distance, similarity of disease mechanism, and PK/PD translatability

Q28. What is adaptive trial design and why is it used in clinical development?

• A fixed protocol with no interim changes; used for marketing only
• A design allowing predefined modifications based on interim data to increase efficiency and ethical benefit
• A manufacturing optimization protocol
• A type of GLP toxicology study

Correct Answer: A design allowing predefined modifications based on interim data to increase efficiency and ethical benefit

Q29. Which regulatory pathway may accelerate approval for drugs that address unmet medical needs or serious conditions?

• Standard patent filing
• Accelerated approval, breakthrough therapy designation, or priority review
• Phase 0 microdosing exclusively
• Bioequivalence waiver

Correct Answer: Accelerated approval, breakthrough therapy designation, or priority review

Q30. Why is reproducibility and GLP compliance in preclinical studies critical for IND submission?

• To enable faster marketing only
• To ensure data integrity, animal welfare, and regulatory confidence in safety assessments
• To replace the need for clinical trials
• To reduce the cost of chemical synthesis

Correct Answer: To ensure data integrity, animal welfare, and regulatory confidence in safety assessments

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