Drug discovery phase MCQs With Answer

Drug discovery phase MCQs With Answer

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Introduction: Drug discovery phase MCQs with Answer is a focused study tool designed for B. Pharm students to master core concepts in drug discovery, including target identification, lead discovery, lead optimization, preclinical studies, ADME/Tox, and clinical trial phases. This concise, keyword-rich introduction covers high-throughput screening, structure–activity relationship (SAR), QSAR, Lipinski’s rules, in silico docking, prodrugs, biomarkers, regulatory filings (IND/NDA) and pharmacokinetics/pharmacodynamics essentials. Engaging and informative, these questions deepen understanding of experimental design, toxicity testing, formulation challenges and regulatory strategy, reinforcing practical knowledge needed for research and industry roles. ‘Now let’s test your knowledge with 30 MCQs on this topic.’

Q1. What is the primary goal of target identification in early drug discovery?

  • Identify molecular target involved in disease pathology
  • Validate safety profile in healthy volunteers
  • Optimize manufacturing yield
  • Apply for marketing approval

Correct Answer: Identify molecular target involved in disease pathology

Q2. Target validation primarily confirms which aspect of a potential drug target?

  • Its causal role in the disease and therapeutic relevance
  • Market demand for a target-based drug
  • Stability during formulation
  • Manufacturing scalability

Correct Answer: Its causal role in the disease and therapeutic relevance

Q3. What is the main purpose of high-throughput screening (HTS)?

  • Rapidly test large chemical libraries for active hits
  • Assess chronic toxicity in animals
  • Measure drug concentrations in patients
  • File an IND application

Correct Answer: Rapidly test large chemical libraries for active hits

Q4. Lead optimization in drug discovery focuses on which objective?

  • Improve potency, selectivity and ADME/Tox properties
  • Draft the final marketing label
  • Perform post-marketing surveillance
  • Scale-up sterile manufacturing

Correct Answer: Improve potency, selectivity and ADME/Tox properties

Q5. Lipinski’s Rule of Five is used to predict which property?

  • Oral bioavailability of small molecule drugs
  • Carcinogenic potential
  • Toxicity in liver cells
  • Parenteral formulation stability

Correct Answer: Oral bioavailability of small molecule drugs

Q6. ADME in pharmacokinetics stands for which of the following?

  • Absorption, Distribution, Metabolism, Excretion
  • Activity, Dose, Metabolism, Efficacy
  • Allocation, Delivery, Modification, Elimination
  • Administration, Dilution, Monitoring, Evaluation

Correct Answer: Absorption, Distribution, Metabolism, Excretion

Q7. IC50 is best defined as which parameter?

  • Concentration of inhibitor that produces 50% inhibition in vitro
  • Dose producing 50% maximum response in humans
  • Time to reach 50% of steady-state concentration
  • Fraction of drug absorbed after oral dose

Correct Answer: Concentration of inhibitor that produces 50% inhibition in vitro

Q8. Which study is typically part of preclinical toxicology assessment?

  • Acute toxicity studies in two mammalian species
  • Phase II efficacy trial in patients
  • Post-marketing adverse event monitoring
  • Stability testing for shelf-life

Correct Answer: Acute toxicity studies in two mammalian species

Q9. The IND application in the United States is submitted to which authority?

  • US FDA (Food and Drug Administration)
  • European Medicines Agency (EMA)
  • World Health Organization (WHO)
  • International Council for Harmonisation (ICH)

Correct Answer: US FDA (Food and Drug Administration)

Q10. Phase I clinical trials primarily assess what?

  • Safety and tolerability in healthy volunteers or patients
  • Long-term efficacy in large populations
  • Post-marketing safety signals
  • Comparative effectiveness versus standard of care

Correct Answer: Safety and tolerability in healthy volunteers or patients

Q11. A biomarker in drug development is best described as:

  • A measurable biological indicator of disease or therapeutic response
  • A formulation excipient that stabilizes the drug
  • A legal document for patent protection
  • A manufacturing quality control parameter

Correct Answer: A measurable biological indicator of disease or therapeutic response

Q12. Structure–activity relationship (SAR) studies investigate:

  • The relationship between chemical structure and biological activity
  • Clinical trial design and endpoints
  • Supply chain logistics for API delivery
  • Marketing strategies for a new drug

Correct Answer: The relationship between chemical structure and biological activity

Q13. QSAR stands for which concept used in computational drug design?

  • Quantitative Structure–Activity Relationship
  • Quality Standards and Regulatory Affairs
  • Quantitative Safety and Risk
  • Quick Synthesis and Reaction

Correct Answer: Quantitative Structure–Activity Relationship

Q14. The purpose of designing a prodrug is usually to:

  • Improve bioavailability, solubility or target delivery
  • Increase the drug’s patent life by default
  • Enhance intrinsic toxicity for efficacy
  • Reduce production costs significantly

Correct Answer: Improve bioavailability, solubility or target delivery

Q15. In silico molecular docking primarily predicts:

  • Binding mode and relative affinity of a ligand to a target
  • Clinical adverse event profiles in humans
  • Optimal manufacturing temperature
  • Pharmacokinetic half-life in patients

Correct Answer: Binding mode and relative affinity of a ligand to a target

Q16. Fragment-based drug design (FBDD) uses which strategy?

  • Start from small chemical fragments and grow or link them into leads
  • Screen marketed drugs for repurposing only
  • Rely solely on natural products for leads
  • Use high-dose toxicity data to design drugs

Correct Answer: Start from small chemical fragments and grow or link them into leads

Q17. Good Laboratory Practice (GLP) ensures what aspect of preclinical studies?

  • Quality, integrity and reproducibility of non-clinical safety data
  • Marketing authorization processes
  • Clinical trial randomization procedures
  • Environmentally sustainable manufacturing

Correct Answer: Quality, integrity and reproducibility of non-clinical safety data

Q18. A lead compound in early discovery is defined as:

  • A molecule with the desired biological activity and acceptable starting properties for optimization
  • The final marketed drug formulation
  • A compound used only for toxicity control
  • A regulatory document summarizing preclinical data

Correct Answer: A molecule with the desired biological activity and acceptable starting properties for optimization

Q19. Which BCS class describes drugs with low solubility and high permeability?

  • BCS Class II
  • BCS Class I
  • BCS Class III
  • BCS Class IV

Correct Answer: BCS Class II

Q20. Therapeutic index (TI) is best described as:

  • Ratio of toxic dose to effective dose, indicating drug safety margin
  • Percentage of drug absorbed systemically
  • Time to peak plasma concentration
  • Rate of drug elimination per hour

Correct Answer: Ratio of toxic dose to effective dose, indicating drug safety margin

Q21. In Michaelis–Menten kinetics, Km represents:

  • Substrate concentration at which reaction velocity is half of Vmax
  • Maximum velocity of the enzyme-catalyzed reaction
  • Time to metabolize 50% of drug
  • Affinity of an inhibitor for an enzyme

Correct Answer: Substrate concentration at which reaction velocity is half of Vmax

Q22. The inhibition constant Ki indicates:

  • Binding affinity of an inhibitor for its target
  • Time required for complete inhibition
  • Maximum inhibitory effect (Emax)
  • Rate of irreversible binding

Correct Answer: Binding affinity of an inhibitor for its target

Q23. Which ADME factor most directly reduces oral bioavailability?

  • Extensive first-pass hepatic metabolism
  • High plasma protein binding
  • Slow renal clearance
  • Large volume of distribution

Correct Answer: Extensive first-pass hepatic metabolism

Q24. Genotoxicity testing is designed to detect:

  • Potential of a compound to cause DNA damage or mutations
  • Immediate allergic reactions in humans
  • Effects on drug taste and odor
  • Chronic cardiovascular toxicity only

Correct Answer: Potential of a compound to cause DNA damage or mutations

Q25. A bioassay in pharmacology is used to measure:

  • Biological potency or activity of a substance in a biological system
  • Concentration of excipients in formulation
  • Cost-effectiveness of a clinical trial
  • Color stability of a suspension

Correct Answer: Biological potency or activity of a substance in a biological system

Q26. A surrogate endpoint or biomarker used in accelerated approval typically serves as:

  • A substitute reasonably likely to predict clinical benefit
  • A manufacturing quality attribute
  • A marketing performance metric
  • A method to reduce preclinical studies

Correct Answer: A substitute reasonably likely to predict clinical benefit

Q27. Orphan drug designation provides what incentive for developers?

  • Regulatory and financial incentives for drugs treating rare diseases
  • Immediate market exclusivity worldwide
  • Exemption from all clinical trials
  • Guaranteed reimbursement by all insurers

Correct Answer: Regulatory and financial incentives for drugs treating rare diseases

Q28. Accelerated approval pathways are often based on which type of data?

  • Surrogate endpoints that are reasonably likely to predict clinical benefit
  • Only long-term mortality data from phase III trials
  • Manufacturing validation batches
  • Preclinical animal efficacy alone

Correct Answer: Surrogate endpoints that are reasonably likely to predict clinical benefit

Q29. Pharmacovigilance primarily involves monitoring which aspect of medicines?

  • Safety and adverse effects after marketing
  • Cost of drug development
  • Physical stability of the bulk drug substance
  • Clinical trial recruitment rates

Correct Answer: Safety and adverse effects after marketing

Q30. The major goal during lead selection is to:

  • Balance potency, selectivity, ADME properties, safety and developability
  • Prioritize only the cheapest compound to manufacture
  • Choose a compound based exclusively on in vitro potency
  • Skip toxicology to speed development

Correct Answer: Balance potency, selectivity, ADME properties, safety and developability

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