Principles of biological standardization MCQs With Answer

Introduction: Principles of biological standardization MCQs With Answer is a focused quiz set designed for M.Pharm students to strengthen their understanding of biological standardization concepts used in evaluating drug potency, safety, and efficacy. This collection covers core principles such as types of bioassays, reference standards, dose–response relationships, parallel line assay assumptions, quantal vs graded responses, potency expression (IU, ED50), precision and accuracy, validation, and regulatory considerations. Each question reinforces theoretical knowledge and practical implications encountered in laboratory bioassays and pharmacological evaluations. Use these MCQs to revise critical concepts, identify gaps, and prepare for exams and viva voce in the subject of Biological Evaluation of Drug Therapy.

Q1. Which of the following best defines biological standardization?

• Quantitative comparison of biological activity of a test preparation with a standard preparation using a biological system
• Chemical analysis to determine molecular weight of biologics
• Clinical trial procedure for monitoring adverse reactions
• Manufacturing protocol for sterile injectable drugs

Correct Answer: Quantitative comparison of biological activity of a test preparation with a standard preparation using a biological system

Q2. What is the primary purpose of using an international standard in biological assays?

• To calibrate analytical instruments for chromatography
• To provide a reference for expressing potency in international units (IU)
• To replace clinical trials in drug approval
• To standardize formulation excipients

Correct Answer: To provide a reference for expressing potency in international units (IU)

Q3. Which bioassay type measures continuous (graded) responses such as blood pressure or enzyme activity?

• Quantal bioassay
• Graded (continuous) bioassay
• Microbiological assay for antibiotics
• Immunoassay for antibodies only

Correct Answer: Graded (continuous) bioassay

Q4. In a quantal dose–response bioassay, which parameter is commonly estimated?

• ED50 (median effective dose)
• Maximum effect (Emax)
• Km of enzyme
• Partition coefficient (log P)

Correct Answer: ED50 (median effective dose)

Q5. Which assumption is essential for applying the parallel line assay method?

• The dose–response curves are parallel and linear over the effective range
• The standard and test have identical chemical composition
• The response is strictly binary with no variability
• The assay uses only one concentration of standard

Correct Answer: The dose–response curves are parallel and linear over the effective range

Q6. What does the slope ratio method compare in biological standardization?

• The steepness (slope) of dose–response lines of test and standard
• The molecular weights of two proteins
• The purity percentages of different batches
• The pH stability profiles of formulations

Correct Answer: The steepness (slope) of dose–response lines of test and standard

Q7. Which statistical parameter is most useful to express the precision of repeated bioassay results?

• Standard deviation or coefficient of variation (CV)
• Partition coefficient
• p-value alone
• Maximum likelihood estimate without intervals

Correct Answer: Standard deviation or coefficient of variation (CV)

Q8. In potency estimation, what does an outcome “relative potency = 0.8” imply?

• The test preparation is 80% as potent as the standard
• The test is 20% purer than the standard
• The test has 80% greater molecular weight
• The test is unsuitable for clinical use

Correct Answer: The test preparation is 80% as potent as the standard

Q9. Which of the following is a critical step when preparing a biological standard for routine assays?

• Stability testing under defined storage conditions
• Ignoring container leakage since biological activity is stable
• Using uncharacterized crude extract as standard
• Altering the standard composition before each assay

Correct Answer: Stability testing under defined storage conditions

Q10. What is the main difference between biological standardization and chemical standardization?

• Biological standardization measures biological activity; chemical standardization measures chemical content or purity
• Biological standardization uses only chromatography; chemical uses only bioassays
• Biological standardization is performed after product release only
• C hemical standardization is obsolete for modern drugs

Correct Answer: Biological standardization measures biological activity; chemical standardization measures chemical content or purity

Q11. Which bioassay design reduces inter-assay variability by testing test and standard simultaneously in the same run?

• Combined or concurrent assay
• Sequential single-run assay
• Historical control assay only
• Calibration curve without standard

Correct Answer: Combined or concurrent assay

Q12. Which endpoint is typical for lethal quantal assays used historically for toxicity determination?

• Death (LD50)
• Change in enzyme Vmax
• Optical density at 260 nm
• Binding affinity (Kd)

Correct Answer: Death (LD50)

Q13. In bioassay validation, which characteristic ensures the assay measures only the intended biological effect?

• Specificity (or selectivity)
• Robustness
• Linearity alone
• Repeatability only

Correct Answer: Specificity (or selectivity)

Q14. What is the role of parallelism testing in comparing a new biologic to a reference standard?

• To confirm that dose–response curves have similar slopes, allowing relative potency calculation
• To compare molecular weight only
• To ensure identical color and odor of formulations
• To determine dissolution profile differences

Correct Answer: To confirm that dose–response curves have similar slopes, allowing relative potency calculation

Q15. Which unit is commonly used to express potency of biologicals standardized against international preparations?

• International Unit (IU)
• Molar concentration (M) only
• Percentage purity
• Pounds per square inch (psi)

Correct Answer: International Unit (IU)

Q16. Which factor should be controlled to minimize biological assay variability due to the biological system?

• Source, age, and health status of the biological material (e.g., animals, cells)
• Color of the assay room walls
• Manufacturer of glassware only
• Type of font used in the data sheet

Correct Answer: Source, age, and health status of the biological material (e.g., animals, cells)

Q17. When is a bioassay result considered valid for potency calculation using a parallel line model?

• When tests of linearity and parallelism are satisfied and variability is acceptable
• When only one concentration of standard gives response
• When pH is not measured
• Whenever the test shows higher activity than standard

Correct Answer: When tests of linearity and parallelism are satisfied and variability is acceptable

Q18. Which regulatory document often provides guidance on biological standardization and assay validation?

• World Health Organization (WHO) guidelines and pharmacopeial monographs
• Local weather reports
• Consumer product safety leaflets for household goods
• Automotive maintenance manuals

Correct Answer: World Health Organization (WHO) guidelines and pharmacopeial monographs

Q19. In a dose–response experiment, what does a shallower slope of the test compared to the standard indicate if parallelism is not met?

• Different biological response dynamics; relative potency estimation may be invalid
• That the test is always more potent than the standard
• That analytical purity is higher for the test
• That potency can be calculated by simple ratio regardless

Correct Answer: Different biological response dynamics; relative potency estimation may be invalid

Q20. Which practice improves the reliability of potency estimates obtained from bioassays?

• Using multiple independent runs with replicate doses and appropriate statistical analysis
• Running a single replicate of a single dose only
• Ignoring outliers without investigation
• Changing assay conditions between standard and test runs

Correct Answer: Using multiple independent runs with replicate doses and appropriate statistical analysis

Download