Quality control for creams and parenterals MCQs With Answer

Quality control for creams and parenterals MCQs With Answer is a focused resource for M.Pharm students preparing for exams and practical assessments in Quality Control & Quality Assurance. This blog presents targeted multiple-choice questions that cover critical testing parameters — from rheology, spreadability, preservative efficacy and assay of creams to sterility, endotoxin testing, particulate analysis, filter validation and container-closure integrity for parenterals. Questions emphasize underlying principles, test methods, acceptance rationale and regulatory expectations, helping students build conceptual depth rather than rote memorization. Use these MCQs to evaluate readiness, identify gaps in laboratory understanding, and reinforce best practices for ensuring safety, efficacy, and compliance of semisolid and parenteral dosage forms.

Q1. What is the primary objective of rheological studies in cream quality control?

• Determine flow and deformation behavior of the semisolid formulation
• Ensure the product is sterile and free from pyrogens
• Measure the level of endotoxins in the cream
• Determine the particle size distribution of suspended solids

Correct Answer: Determine flow and deformation behavior of the semisolid formulation

Q2. The common laboratory method for assessing spreadability of a topical cream is based on which principle?

• Measuring time taken for two glass slides separated by the cream to slide apart under a specified weight
• Measuring the viscosity using a capillary viscometer at high shear
• Determining the surface tension of the cream using a tensiometer
• Measuring the drop size after atomization through a nozzle

Correct Answer: Measuring time taken for two glass slides separated by the cream to slide apart under a specified weight

Q3. Why is pH measurement critical in quality control of creams?

• pH affects drug stability, preservative efficacy and skin compatibility
• pH directly indicates sterility status of the cream
• Lower pH guarantees better spreadability
• pH measurement replaces the need for preservative efficacy testing

Correct Answer: pH affects drug stability, preservative efficacy and skin compatibility

Q4. What does the homogeneity test for creams primarily assess?

• Uniform distribution of active pharmaceutical ingredient throughout the batch
• The sterility of the cream after packaging
• The endotoxin level in the formulation
• The water activity of the sample

Correct Answer: Uniform distribution of active pharmaceutical ingredient throughout the batch

Q5. The Preservative Efficacy Test (PET) is also known as which of the following?

• Antimicrobial Effectiveness Test
• Sterility Assurance Test
• Endotoxin Quantification Test
• Container Closure Integrity Test

Correct Answer: Antimicrobial Effectiveness Test

Q6. One main advantage of membrane filtration sterility testing for parenterals is:

• Ability to examine larger sample volumes and recover microorganisms that may be trapped
• Shorter incubation time compared to direct inoculation
• Direct quantitation of endotoxin levels during the sterility test
• No need for aseptic technique when performing the test

Correct Answer: Ability to examine larger sample volumes and recover microorganisms that may be trapped

Q7. The classical rabbit pyrogen test for parenterals has largely been replaced by which test?

• Bacterial Endotoxin Test (Limulus Amebocyte Lysate, LAL)
• Membrane filtration sterility test
• Thiotepa clotting assay
• Gram staining of product samples

Correct Answer: Bacterial Endotoxin Test (Limulus Amebocyte Lysate, LAL)

Q8. The Limulus amebocyte lysate (LAL) test detects pyrogens based on which principle?

• Clot formation or color/turbidity change in the lysate on contact with gram-negative endotoxin
• Measurement of pH change caused by bacterial metabolites
• Growth of bacteria on selective media from the sample
• UV absorption by lipopolysaccharides

Correct Answer: Clot formation or color/turbidity change in the lysate on contact with gram-negative endotoxin

Q9. For parenteral injections, the light-obscuration particle count test is primarily intended to detect:

• Sub-visible particulate matter that could cause emboli or immune reactions
• Endotoxin concentration in EU/mL
• Microbial contamination in aerobic cultures
• Residual solvent levels

Correct Answer: Sub-visible particulate matter that could cause emboli or immune reactions

Q10. The purpose of container-closure integrity testing for sterile parenterals is to:

• Verify the sterile barrier and detect leaks that could permit microbial ingress
• Measure the extractables and leachables profile
• Quantify residual moisture content
• Assess the pH drift during storage

Correct Answer: Verify the sterile barrier and detect leaks that could permit microbial ingress

Q11. Which organism is commonly used for bacterial retention challenge during filter validation of 0.2 µm sterilizing-grade filters?

• Brevundimonas (Pseudomonas) diminuta
• Staphylococcus aureus
• Escherichia coli O157:H7
• Bacillus subtilis

Correct Answer: Brevundimonas (Pseudomonas) diminuta

Q12. Standard sterility testing of parenterals requires incubation in which pair of media to detect a broad spectrum of contaminants?

• Fluid thioglycollate medium and soybean-casein digest medium (SCDM)
• Blood agar and MacConkey agar
• Sabouraud dextrose broth and nutrient broth
• Thioglycollate with antibiotic and buffered saline

Correct Answer: Fluid thioglycollate medium and soybean-casein digest medium (SCDM)

Q13. The major source of pyrogenic reactions in parenteral products is:

• Endotoxin from Gram-negative bacteria
• Peptidoglycan from Gram-positive bacteria
• Mycotoxins from fungal contamination
• Viral particles surviving sterilization

Correct Answer: Endotoxin from Gram-negative bacteria

Q14. In rheology, thixotropy of a cream means:

• Viscosity decreases under shear and recovers over time when shear is removed
• Viscosity increases permanently after shearing
• The cream shows Newtonian behavior at all shear rates
• Viscosity is independent of temperature changes

Correct Answer: Viscosity decreases under shear and recovers over time when shear is removed

Q15. Why is water activity (aw) important in creams and other semisolids?

• High water activity promotes microbial growth and affects preservative efficiency
• Water activity determines the color of the cream
• Low water activity increases the pH of the formulation
• Water activity is directly equivalent to total water content

Correct Answer: High water activity promotes microbial growth and affects preservative efficiency

Q16. For semisolid dosage forms like creams, content uniformity is most appropriately assessed by:

• Assaying multiple samples taken from different areas of a batch to ensure uniform distribution
• Measuring the average weight of containers only
• Performing a single assay on a pooled sample from the batch
• Relying solely on visual homogeneity inspection

Correct Answer: Assaying multiple samples taken from different areas of a batch to ensure uniform distribution

Q17. Which approach is preferred for sterilizing heat-labile parenteral solutions containing small molecules?

• Sterile filtration (0.2 µm) followed by aseptic filling
• Autoclaving at 121°C for 15 minutes
• Dry-heat sterilization at 160°C
• Gamma irradiation of the filled product

Correct Answer: Sterile filtration (0.2 µm) followed by aseptic filling

Q18. The typical target Sterility Assurance Level (SAL) for terminally sterilized parenteral products is:

• 10^-6 probability of a viable microorganism surviving
• 10^-3 probability of contamination
• 100% sterility guaranteed
• 10^-9 probability of microbial growth in the product

Correct Answer: 10^-6 probability of a viable microorganism surviving

Q19. Which Limulus Amebocyte Lysate (LAL) assay format is considered qualitative rather than quantitative?

• Gel-clot LAL assay
• Turbidimetric chromogenic LAL assay
• Endpoint chromogenic LAL assay
• Kinetic turbidimetric LAL assay

Correct Answer: Gel-clot LAL assay

Q20. A true stability-indicating analytical method for a cream or parenteral product must:

• Resolve the active drug from its degradation products and quantify the active accurately
• Measure only the total organic content, ignoring degradation peaks
• Assess only the appearance and pH while ignoring assay specificity
• Be based solely on UV absorbance without chromatographic separation

Correct Answer: Resolve the active drug from its degradation products and quantify the active accurately

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