Analysis of raw materials in QA/QC MCQs With Answer

Introduction: Analysis of raw materials in QA/QC is a critical component of pharmaceutical quality assurance and control. This blog provides M.Pharm students with focused multiple-choice questions covering sampling strategies, identification tests, pharmacopeial specifications, analytical techniques (HPLC, GC, IR, titration), impurities testing, microbial and endotoxin limits, residual solvents, heavy metals, and vendor qualification. Questions emphasize practical interpretation of certificates of analysis, acceptance criteria, stability considerations, and regulatory expectations under GMP. These MCQs are designed to deepen understanding, reinforce method selection and validation concepts, and prepare students for clinical inspections and real-world QA/QC decision-making.

Q1. What is the primary purpose of establishing a raw material specification in QA/QC?

• To define manufacturing procedures for the material
• To document vendor pricing and delivery schedules
• To set acceptance criteria and analytical tests ensuring material quality
• To record the environmental impact of raw material sourcing

Correct Answer: To set acceptance criteria and analytical tests ensuring material quality

Q2. Which sampling plan is most appropriate to obtain a representative sample from a large homogeneous powder batch?

• Single grab sample from the top of the bulk
• Incremental composite sampling from multiple locations
• Final fill sample only after processing
• Sampling only from the corners of the container

Correct Answer: Incremental composite sampling from multiple locations

Q3. When verifying identity of an organic raw material, which pair of orthogonal techniques provides complementary confirmation?

• UV spectrophotometry and Karl Fischer titration
• HPLC retention time and FTIR spectrum
• Loss on drying and melting point
• Organoleptic test and pH measurement

Correct Answer: HPLC retention time and FTIR spectrum

Q4. Which test is the most appropriate to quantify trace metallic contaminants in a starting material?

• Titrimetric assay
• ICP-MS (Inductively Coupled Plasma Mass Spectrometry)
• UV-visible spectrophotometry
• Droplet titration

Correct Answer: ICP-MS (Inductively Coupled Plasma Mass Spectrometry)

Q5. For water content determination in a hygroscopic API, which technique gives the most specific and accurate result?

• Loss on drying (LOD) at 105°C
• Karl Fischer titration
• Thermogravimetric analysis without calibration
• Gravimetric sieving

Correct Answer: Karl Fischer titration

Q6. Which parameter is critical to monitor for a raw material that is used as an active pharmaceutical ingredient in inhalation products?

• Bulk color only
• Particle size distribution and aerodynamic properties
• Tap density exclusively
• Solubility in ethanol only

Correct Answer: Particle size distribution and aerodynamic properties

Q7. A Certificate of Analysis (CoA) shows assay within limits but impurities above acceptance. What is the correct QA action?

• Release material based only on assay
• Quarantine material and investigate impurity source
• Ignore CoA and rely on supplier reputation
• Blend with other lots to dilute impurities without testing

Correct Answer: Quarantine material and investigate impurity source

Q8. Which method is most suitable for detection and quantification of residual organic solvents in raw materials?

• Atomic absorption spectroscopy
• Gas chromatography with suitable detector
• Polarimetry
• Near-infrared moisture analysis

Correct Answer: Gas chromatography with suitable detector

Q9. During raw material testing, the term “shelf-life” primarily refers to which consideration?

• Time taken to manufacture the material
• Duration material meets specification under labelled storage conditions
• Time for vendor to deliver next shipment
• Period for which vendor warranty applies

Correct Answer: Duration material meets specification under labelled storage conditions

Q10. Which microbial limit test is most appropriate for a non-sterile botanical raw material used in solid oral dosage forms?

• Sterility test only
• Total aerobic microbial count and specified objectionable organisms
• Endotoxin test exclusively
• Mycoplasma PCR only

Correct Answer: Total aerobic microbial count and specified objectionable organisms

Q11. Which of the following is a critical attribute to validate for an HPLC method used in raw material assay?

• Color of mobile phase
• Specificity, accuracy, precision, linearity and robustness
• Operator’s handwriting style
• Supplier of solvents only

Correct Answer: Specificity, accuracy, precision, linearity and robustness

Q12. What is the primary regulatory reason to maintain retention samples of raw materials?

• To reduce storage costs
• To allow re-analysis in case of complaint or stability issues
• To use as production material later
• To transfer to another site for disposal

Correct Answer: To allow re-analysis in case of complaint or stability issues

Q13. Which test would you select to detect inorganic impurities (ash content) in an excipient?

• Loss on drying
• Total ash or sulfated ash determination
• HPLC assay
• IR peak ratio analysis

Correct Answer: Total ash or sulfated ash determination

Q14. In vendor qualification for raw materials, which document provides evidence of consistent quality from the supplier?

• Purchase order number only
• History of batch CoAs, audits, and quality agreements
• Vendor marketing brochure
• Vendor’s CEO biography

Correct Answer: History of batch CoAs, audits, and quality agreements

Q15. What is the main advantage of using reference standards certified by pharmacopeias in raw material testing?

• They are cheaper than in-house standards
• They provide traceability and known purity for accurate quantitation
• They eliminate the need for method validation
• They replace all routine QC tests

Correct Answer: They provide traceability and known purity for accurate quantitation

Q16. Which stability-related test on raw materials helps predict potential interactions during long-term storage?

• Accelerated stability studies under controlled temperature and humidity
• Vendor credit term evaluation
• Visual inspection only
• Single-point moisture check at receipt

Correct Answer: Accelerated stability studies under controlled temperature and humidity

Q17. For a highly potent API, which additional QA control is essential at the raw material stage?

• Only visual inspection
• Dedicated containment, cross-contamination controls and potency limits
• Reduced sampling frequency
• Use of generic packaging to save costs

Correct Answer: Dedicated containment, cross-contamination controls and potency limits

Q18. When performing identity testing by IR, what is a critical limitation to consider?

• IR provides excellent quantitation for trace impurities
• IR may not distinguish structural isomers with very similar functional groups
• IR measures particle size directly
• IR is unaffected by excipient blends

Correct Answer: IR may not distinguish structural isomers with very similar functional groups

Q19. Which parameter is assessed by a limit test for heavy metals in a raw material?

• Total microbial load
• Total concentration of specified heavy metal contaminants (e.g., lead, arsenic)
• pH of aqueous extract
• Optical rotation

Correct Answer: Total concentration of specified heavy metal contaminants (e.g., lead, arsenic)

Q20. In evaluating a new supplier, which analytical evidence best supports acceptance of their raw material?

• Single internal test report without traceability
• Comprehensive CoA, batch-to-batch consistency data, and on-site audit findings
• Lowest price per kg
• Supplier’s promotional claims

Correct Answer: Comprehensive CoA, batch-to-batch consistency data, and on-site audit findings

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