Expiration dating of dosage forms MCQs With Answer

Expiration dating of dosage forms is essential for ensuring drug safety, efficacy and regulatory compliance. This topic covers principles of stability testing, shelf-life determination, degradation pathways (hydrolysis, oxidation, photolysis), ICH and USP guidelines, accelerated and long-term studies, container-closure effects, and stability-indicating analytical methods. B. Pharm students must understand kinetics, Arrhenius extrapolation, forced-degradation studies, preservative efficacy, refrigeration and in-use stability, and labeling requirements such as expiry date versus beyond-use date. Practical knowledge helps in formulation selection, packaging, and quality control to prevent therapeutic failure or toxicity. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which study is primarily used to establish the shelf-life of a drug under recommended storage conditions?

• Accelerated stability study
• Stress degradation study
• Long‑term (real‑time) stability study
• Photostability test

Correct Answer: Long‑term (real‑time) stability study

Q2. According to ICH guidelines, which document primarily describes stability testing for new drug substances and products?

• ICH Q1A(R2)
• ICH Q3A
• ICH Q6A
• ICH Q9

Correct Answer: ICH Q1A(R2)

Q3. Which degradation pathway is most likely for ester-containing liquid formulations stored at high humidity?

• Photodegradation
• Hydrolysis
• Oxidation
• Polymerization

Correct Answer: Hydrolysis

Q4. A stability‑indicating method must primarily do what?

• Measure total solid content
• Separate and quantify the active from its degradation products
• Determine particle size distribution
• Assess viscosity changes

Correct Answer: Separate and quantify the active from its degradation products

Q5. Which temperature and humidity condition is commonly used for accelerated stability testing of non‑biological solid oral dosage forms?

• 5°C ±3°C, ambient RH
• 30°C ±2°C / 35% RH
• 40°C ±2°C / 75% RH
• 25°C ±2°C / 60% RH

Correct Answer: 40°C ±2°C / 75% RH

Q6. What does t90 represent in stability kinetics for a drug product?

• Time for 90% of container integrity to fail
• Time to reach 90% degradation
• Time by which 90% of initial potency remains
• The temperature at which 90% of degradation occurs

Correct Answer: Time by which 90% of initial potency remains

Q7. Which kinetic model commonly describes the degradation of many drug substances in solution?

• Zero‑order only
• Second‑order only
• First‑order
• Michaelis‑Menten kinetics

Correct Answer: First‑order

Q8. The Arrhenius equation is used in stability studies to:

• Predict photodegradation under UV light
• Extrapolate shelf‑life from accelerated data to normal storage conditions
• Measure relative humidity inside packaging
• Determine microbial limits

Correct Answer: Extrapolate shelf‑life from accelerated data to normal storage conditions

Q9. In forced degradation studies, which stress condition is NOT typically applied?

• Acid and base hydrolysis
• Thermal stress
• Oxidative stress
• Microbial inoculation stress

Correct Answer: Microbial inoculation stress

Q10. Photostability testing per ICH Q1B is especially important for compounds that:

• Are non‑chromophoric
• Have known light‑sensitive functional groups
• Are gaseous at room temperature
• Contain only inorganic salts

Correct Answer: Have known light‑sensitive functional groups

Q11. Which factor related to container-closure systems can accelerate drug degradation?

• Low oxygen permeability for oxygen‑sensitive drugs
• High moisture vapor transmission rate for hygroscopic drugs
• Opaque packaging for light‑sensitive drugs
• Use of high-barrier laminates for volatile drugs

Correct Answer: High moisture vapor transmission rate for hygroscopic drugs

Q12. For parenteral aqueous solutions, which preservative concern is directly tied to stability and expiration dating?

• Preservative color change
• Loss of antimicrobial efficacy over time
• Increase in pH beyond ionization range
• Decrease in osmolarity

Correct Answer: Loss of antimicrobial efficacy over time

Q13. What is the regulatory term used when a manufacturer specifies that a drug should not be used after a certain date?

• Beyond‑use date
• Retest period
• Expiry date
• Manufacturing date

Correct Answer: Expiry date

Q14. How does a ‘retest period’ differ from an ‘expiry date’ for active pharmaceutical ingredients (APIs)?

• Retest is for finished products; expiry for raw materials
• Retest indicates time to reassess quality; expiry indicates time beyond which product should not be used
• They are identical terms used interchangeably
• Retest is always longer than expiry

Correct Answer: Retest indicates time to reassess quality; expiry indicates time beyond which product should not be used

Q15. Which analytical attribute is most critical to monitor during stability studies to demonstrate maintained potency?

• Assay of active pharmaceutical ingredient
• Container weight
• pH indicator color only
• Viscosity of solution when unchanged

Correct Answer: Assay of active pharmaceutical ingredient

Q16. Bracketing and matrixing designs in stability studies are used to:

• Replace the need for any real‑time testing
• Reduce the number of samples and storage conditions tested while still ensuring coverage
• Increase the frequency of testing for every batch
• Only apply to biological vaccines

Correct Answer: Reduce the number of samples and storage conditions tested while still ensuring coverage

Q17. Which statement about biologicals (e.g., monoclonal antibodies) and expiration dating is true?

• They are not affected by temperature and can be stored at room temperature indefinitely
• Stability is highly dependent on cold chain and specific storage conditions
• Lyophilization removes all stability concerns after reconstitution
• Photostability is the only concern

Correct Answer: Stability is highly dependent on cold chain and specific storage conditions

Q18. What is the primary objective of in‑use stability studies?

• Assess long‑term stability of unopened product
• Evaluate quality and safety after the product is opened, reconstituted or diluted during use
• Determine packaging color stability
• Measure microbial content of raw materials

Correct Answer: Evaluate quality and safety after the product is opened, reconstituted or diluted during use

Q19. Which result from accelerated studies would most likely invalidate Arrhenius extrapolation to predict shelf‑life?

• Simple first‑order degradation at all temperatures
• Change in degradation mechanism between accelerated and real‑time conditions
• Linear relationship between ln(k) and 1/T
• Consistent activation energy across temperatures

Correct Answer: Change in degradation mechanism between accelerated and real‑time conditions

Q20. What is a common acceptance criterion for assay decline when establishing expiry (t90) for many small molecule drugs?

• Assay must remain ≥50% of label claim at expiry
• Assay must remain ≥90% of label claim at expiry
• Assay may rise above 110% at expiry
• No assay requirement applies

Correct Answer: Assay must remain ≥90% of label claim at expiry

Q21. Which packaging choice best protects a light‑sensitive drug from photodegradation?

• Clear glass ampoules
• Amber glass or opaque secondary packaging
• Thin polyethylene film with UV transmission
• Aluminum blister with transparent film

Correct Answer: Amber glass or opaque secondary packaging

Q22. For a lyophilized sterile powder intended for reconstitution, the expiration dating of the dry cake is based on:

• Microbial growth in the reconstituted solution only
• Stability of the dry powder under recommended storage conditions
• Stability only after reconstitution
• Color changes in the vial cap

Correct Answer: Stability of the dry powder under recommended storage conditions

Q23. Which parameter is specifically assessed by the antimicrobial effectiveness test (AET) during stability studies?

• pH stability over time
• Ability of preservative system to control microbial growth during product use
• Viscosity change under shear
• Oxidative degradation rate

Correct Answer: Ability of preservative system to control microbial growth during product use

Q24. What does ICH Q1E address that is important for expiration dating strategies?

• Pharmacovigilance reporting
• Evaluation of stability data and statistical approaches for shelf‑life estimation
• Biological assay validation
• Packaging color specifications

Correct Answer: Evaluation of stability data and statistical approaches for shelf‑life estimation

Q25. Which is a key difference between ‘expiry date’ and ‘beyond‑use date’ (BUD) commonly applied in pharmacy practice?

• Expiry date is assigned by the pharmacist; BUD is assigned by manufacturer
• Expiry date is based on manufacturer stability data; BUD is for compounded or repackaged products with limited data
• They are synonymous
• BUD is always longer than expiry date

Correct Answer: Expiry date is based on manufacturer stability data; BUD is for compounded or repackaged products with limited data

Q26. Which analytical approach is most appropriate to detect unknown degradation products formed during forced degradation?

• Visual inspection only
• Non‑specific titration
• Stability‑indicating HPLC coupled with photodiode array or MS detection
• Gravimetric analysis

Correct Answer: Stability‑indicating HPLC coupled with photodiode array or MS detection

Q27. A drug product shows a significant increase in impurity levels only after exposure to oxygen. Which mitigation is most appropriate for expiry date extension?

• Store at higher humidity
• Change container‑closure to an oxygen‑impermeable system or add antioxidant
• Expose to light to reduce oxygen
• Increase storage temperature

Correct Answer: Change container‑closure to an oxygen‑impermeable system or add antioxidant

Q28. Which is true about the use of accelerated stability data for labelling storage instructions?

• Accelerated data alone always justify labeling at refrigerator temperatures
• Accelerated studies can support storage condition decisions but must be confirmed by real‑time data
• Accelerated studies are irrelevant for labeling
• Accelerated data replace the need for ICH studies

Correct Answer: Accelerated studies can support storage condition decisions but must be confirmed by real‑time data

Q29. What is an appropriate action if a batch fails a stability specification before its labeled expiry date?

• Extend the expiry date for that batch
• Investigate root cause, quarantine affected stock, and notify regulatory authorities as required
• Ignore the failure if assay is within ±10%
• Only change packaging color

Correct Answer: Investigate root cause, quarantine affected stock, and notify regulatory authorities as required

Q30. Which statement best describes ‘in‑use’ or ‘open‑container’ stability data needed for multi‑dose products?

• Shows how long unopened product can be stored at high temperatures
• Documents quality after repeated opening, handling, dosing and storage under simulated use conditions
• Is unnecessary if product passed long‑term stability
• Only applies to solid tablets

Correct Answer: Documents quality after repeated opening, handling, dosing and storage under simulated use conditions