Process validation for coated tablets MCQs With Answer

Introduction

Process validation for coated tablets is a critical area in pharmaceutical manufacturing that ensures consistency, quality, and regulatory compliance of the final dosage form. This blog focuses on validation principles specific to film-coated and sugar-coated tablets, highlighting critical quality attributes (CQAs), critical process parameters (CPPs), sampling strategies, in-process controls, and lifecycle approach per regulatory guidance. M.Pharm students will find focused multiple-choice questions that probe coating process optimization, scale-up challenges, analytical and PAT tools, statistical evaluation, and troubleshooting common coating defects. These MCQs are designed to deepen understanding and prepare students for academic exams and practical validation tasks in industry.

Q1. Which of the following is the most critical quality attribute (CQA) directly affected by the tablet coating process?

  • Dissolution profile of the finished tablet
  • Tablet core porosity
  • API chemical structure
  • Packaging material

Correct Answer: Dissolution profile of the finished tablet

Q2. According to the FDA process validation lifecycle, which stage involves defining commercial manufacturing process and identifying CPPs and CQAs?

  • Continued Process Verification
  • Process Qualification
  • Process Design
  • Change Control

Correct Answer: Process Design

Q3. In coating operations, which parameter most directly influences film thickness and weight gain per tablet?

  • Pan speed alone
  • Spray rate and solids content of coating suspension
  • Die fill depth
  • Tablet core assay

Correct Answer: Spray rate and solids content of coating suspension

Q4. Which PAT (Process Analytical Technology) tool is commonly used for real-time monitoring of coating uniformity by measuring film moisture or solvent content?

  • Near Infrared Spectroscopy (NIR)
  • High Performance Liquid Chromatography (HPLC)
  • Gas Chromatography (GC)
  • Thermogravimetric Analysis (TGA)

Correct Answer: Near Infrared Spectroscopy (NIR)

Q5. A common physical defect characterized by coarse, rough surface on film-coated tablets is known as:

  • Pitting
  • Orange peel
  • Bridging
  • Blooming

Correct Answer: Orange peel

Q6. Which of the following is a critical process parameter (CPP) that affects adhesion and plasticizer distribution in film coating?

  • Inlet air temperature and humidity
  • API particle size in the core
  • Tablet imprint depth
  • Final packaged carton dimensions

Correct Answer: Inlet air temperature and humidity

Q7. During scale-up of coating from lab to production, which dimensionless factor is most useful to maintain similar droplet behavior?

  • Reynolds number and spray droplet Weber number equivalence
  • Tablet diameter ratio only
  • Number of coating pans
  • API potency

Correct Answer: Reynolds number and spray droplet Weber number equivalence

Q8. Which in-process control is most appropriate to monitor to avoid overwetting and sticking during aqueous film coating?

  • Core tablet tensile strength
  • Outlet air temperature and tablet bed temperature
  • Colour of the coating suspension
  • Final tablet blister integrity

Correct Answer: Outlet air temperature and tablet bed temperature

Q9. For validation qualification of a coating process, the minimum number of consecutive batches typically recommended by regulatory guidance to demonstrate reproducibility is:

  • One commercial batch
  • Two consecutive batches
  • Three consecutive batches
  • Ten consecutive batches

Correct Answer: Three consecutive batches

Q10. Which statistical index indicates whether a coating process is capable of meeting specification limits with adequate margin (commonly used target)?

  • R-squared
  • Process capability index (Cpk) ≥1.33
  • p-value < 0.05
  • Standard deviation alone

Correct Answer: Process capability index (Cpk) ≥1.33

Q11. In tablet coating validation, which sampling plan best supports demonstrating batch uniformity for coating weight gain?

  • Single tablet from the batch center
  • Random composite of all tablets in a batch
  • Stratified sampling from multiple locations (top, middle, bottom of bed)
  • Only off-specification tablets

Correct Answer: Stratified sampling from multiple locations (top, middle, bottom of bed)

Q12. Which coating defect results from rapid solvent evaporation causing film cracking or chipping?

  • Bridging
  • Cracking
  • Chalking
  • Peeling due to plasticizer excess

Correct Answer: Cracking

Q13. For enteric-coated tablets, what is the primary CQA that must be validated specifically for the coating?

  • Immediate disintegration in 0.1 N HCl
  • Resistance to acid (no release in gastric pH) and release in intestinal pH
  • Uniform colour only
  • Moisture uptake during storage

Correct Answer: Resistance to acid (no release in gastric pH) and release in intestinal pH

Q14. Which device adjustment in a spray coating system most directly changes droplet size?

  • Atomization air pressure
  • Coating suspension pH
  • Tablet core hardness
  • Final blister pack sealing torque

Correct Answer: Atomization air pressure

Q15. Residual solvent limits in coatings are controlled primarily because of:

  • Effect on tablet color only
  • Toxicity risks, quality and stability concerns
  • Increase in tablet hardness
  • Enhancement of dissolution rate

Correct Answer: Toxicity risks, quality and stability concerns

Q16. Which accelerated stability test parameter is most relevant to evaluate coating adhesion and gloss retention?

  • Storage under refrigerated conditions only
  • High humidity and elevated temperature stress (e.g., 40°C/75% RH)
  • Immersion in 0.1 N HCl for 1 hour only
  • Gamma irradiation at production dose

Correct Answer: High humidity and elevated temperature stress (e.g., 40°C/75% RH)

Q17. During coating validation, an observed upward trend in coating weight variability across batches should prompt investigation of which root cause first?

  • API polymorphic form change
  • Variability in solids content of coating suspension or spray rate drift
  • Change in tablet blister carton supplier
  • Analytical HPLC column age

Correct Answer: Variability in solids content of coating suspension or spray rate drift

Q18. Which of the following is an appropriate acceptance criterion for content uniformity after coating when no assay-affecting interactions are expected?

  • All tablets must be within 50–150% of label claim
  • Use USP content uniformity limits (e.g., acceptance value criteria) or defined assay limits typically 85–115%
  • Only average assay matters, individual tablets not required
  • Assay can vary widely as long as dissolution passes

Correct Answer: Use USP content uniformity limits (e.g., acceptance value criteria) or defined assay limits typically 85–115%

Q19. Which technique is most suitable for measuring film coating thickness nondestructively during development?

  • Cross-sectional microscopy only (destructive)
  • Terahertz pulsed imaging or optical coherence tomography (nondestructive)
  • Loss on drying of the core
  • Friability test

Correct Answer: Terahertz pulsed imaging or optical coherence tomography (nondestructive)

Q20. A validated coating process requires periodic re-evaluation. Which activity best describes Continued Process Verification (CPV) for coated tablets?

  • One-time qualification of equipment
  • Ongoing monitoring of critical parameters and product quality attributes with trending and corrective actions
  • Replacing analytical methods annually regardless of performance
  • Performing full revalidation after every batch

Correct Answer: Ongoing monitoring of critical parameters and product quality attributes with trending and corrective actions

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