Evaluation of semisolid dosage forms – parameters and techniques MCQs With Answer

Introduction: Evaluation of semisolid dosage forms is essential in pharmaceutical quality control to ensure safety, efficacy and patient acceptability of ointments, creams, gels and pastes. This topic covers key parameters and techniques such as appearance, odor, pH, viscosity and rheology, spreadability, extrudability, homogeneity, drug content, in vitro drug release and diffusion (Franz cell), microbial limits and preservative efficacy, stability testing, and packaging compatibility. Understanding methods like Brookfield viscometry, texture analysis, centrifugation, microscopy for particle size, and HPLC/UV assays helps B.Pharm students design, analyze and troubleshoot semisolid products. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What parameter primarily assesses the ease with which a semisolid spreads over skin?

• Viscosity measurement using a viscometer
• Spreadability or slip test (e.g., parallel plate method)
• pH determination with a pH meter
• Microbial limit test

Correct Answer: Spreadability or slip test (e.g., parallel plate method)

Q2. Which instrument is most commonly used to measure the apparent viscosity of ointments and gels?

• Brookfield viscometer
• Franz diffusion cell
• Texture analyzer
• UV-Visible spectrophotometer

Correct Answer: Brookfield viscometer

Q3. Which test evaluates the ability of a preservative system in a semisolid to inhibit microbial growth?

• Viscosity profiling
• Antioxidant assay
• Preservative efficacy test (challenge test)
• pH stability test

Correct Answer: Preservative efficacy test (challenge test)

Q4. In in vitro release testing of topical semisolids, which apparatus is commonly used to study drug diffusion across a membrane?

• Autoclave
• Franz diffusion cell
• Centrifuge
• pH meter

Correct Answer: Franz diffusion cell

Q5. Non-Newtonian, shear-thinning behavior often seen in gels is best described as:

• Viscosity increases with increasing shear rate
• Viscosity decreases with increasing shear rate
• Viscosity remains constant regardless of shear
• Viscosity fluctuates randomly with shear

Correct Answer: Viscosity decreases with increasing shear rate

Q6. Which parameter is most critical for assessing the uniform distribution of drug in a semisolid?

• Spreadability
• Homogeneity or content uniformity test
• pH
• Viscosity

Correct Answer: Homogeneity or content uniformity test

Q7. Which analytical technique is typically used for quantitative assay of drug in a semisolid formulation?

• Microscopy
• High-performance liquid chromatography (HPLC)
• Texture profile analysis
• Spreadability test

Correct Answer: High-performance liquid chromatography (HPLC)

Q8. What does the occlusion factor measure for topical semisolid formulations?

• Ability to form a film and reduce transepidermal water loss
• pH stability under heat
• Drug partition coefficient in skin
• Preservative efficacy

Correct Answer: Ability to form a film and reduce transepidermal water loss

Q9. Which technique assesses mechanical properties like firmness and adhesiveness of a semisolid?

• Texture analyzer
• pH meter
• Franz diffusion cell
• Brookfield viscometer only

Correct Answer: Texture analyzer

Q10. Particle size measurement in creams and ointments is important because it influences:

• Color only
• Drug release, stability and skin penetration
• pH exclusively
• Viscosity exclusively

Correct Answer: Drug release, stability and skin penetration

Q11. Which of the following is a common test for physical stability of emulsified semisolids?

• Zeta potential measurement
• Freeze-thaw cycling and centrifugation
• pH titration only
• Antimicrobial assay

Correct Answer: Freeze-thaw cycling and centrifugation

Q12. Which parameter is directly measured to assess chemical stability of active in a semisolid?

• Viscosity profile
• Drug assay over time (degradation studies)
• Spreadability
• Texture analysis

Correct Answer: Drug assay over time (degradation studies)

Q13. How is extrudability of a semisolid typically evaluated?

• By measuring the force required to expel product from a tube
• By determining pH change during storage
• By measuring particle size distribution
• By HPLC assay only

Correct Answer: By measuring the force required to expel product from a tube

Q14. Which property of an emulsion-based ointment can be inferred from measuring zeta potential?

• Rheological exponent
• Electrostatic stability against coalescence
• Drug chemical degradation rate
• Color stability

Correct Answer: Electrostatic stability against coalescence

Q15. Skin irritation or sensitization testing for semisolids is primarily intended to detect:

• Changes in viscosity
• Local adverse reactions like erythema and edema
• Microbial contamination
• Packaging compatibility

Correct Answer: Local adverse reactions like erythema and edema

Q16. Which solvent system is often used to extract drug from a semisolid for quantitative analysis?

• Appropriate organic or aqueous solvent validated for solubility and recovery
• Pure water only irrespective of drug solubility
• Air drying and weighing
• Direct spectrophotometry on intact product always

Correct Answer: Appropriate organic or aqueous solvent validated for solubility and recovery

Q17. The term “pseudoplastic flow” in semisolids corresponds to which behavior?

• Viscosity increases with time at constant shear
• Viscosity decreases with increasing shear rate (shear-thinning)
• Viscosity increases with shear rate (shear-thickening)
• Viscosity independent of shear rate (Newtonian)

Correct Answer: Viscosity decreases with increasing shear rate (shear-thinning)

Q18. Which test helps determine the rate-limiting step in topical drug delivery from a semisolid?

• pH measurement
• In vitro permeation and diffusion studies across skin or membrane
• Colorimetry
• Viscosity alone

Correct Answer: In vitro permeation and diffusion studies across skin or membrane

Q19. What is the significance of measuring spread area in semisolid evaluation?

• It indicates preservative efficacy
• It helps assess ease of application and uniform coverage
• It determines microbial contamination
• It measures pH drift on skin

Correct Answer: It helps assess ease of application and uniform coverage

Q20. For an ointment base, which property most influences drug release rate?

• Base composition and its hydrophilic-lipophilic balance
• Tube color used for packaging
• Manufacturer’s name only
• Font size on the label

Correct Answer: Base composition and its hydrophilic-lipophilic balance

Q21. Which method is useful to evaluate homogeneity of colored or particulate-loaded semisolids?

• Microscopic examination and content uniformity of sampled portions
• pH meter readings
• Rheological flow curve alone
• Antimicrobial challenge test only

Correct Answer: Microscopic examination and content uniformity of sampled portions

Q22. Microbial limit tests for semisolid dosage forms are intended to:

• Quantify preservative concentration chemically
• Ensure total aerobic microbial count and absence of specified pathogens
• Measure viscosity changes caused by microbes
• Assess skin penetration depth

Correct Answer: Ensure total aerobic microbial count and absence of specified pathogens

Q23. Which parameter should be monitored during accelerated stability studies of semisolids?

• Only label design
• Physical appearance, pH, viscosity, drug content and microbial limits
• Texture analyzer calibration alone
• Tube cap color only

Correct Answer: Physical appearance, pH, viscosity, drug content and microbial limits

Q24. The spreadability test using two glass slides mainly measures:

• Microbial contamination
• Work required to spread the formulation (ease of spreading)
• Chemical stability at high temperature
• pH at different shear rates

Correct Answer: Work required to spread the formulation (ease of spreading)

Q25. Which factor can significantly affect the rheological profile of a semisolid?

• Concentration and type of gelling or thickening agent
• Manufacturer logo
• Label font color
• Time of day when manufactured

Correct Answer: Concentration and type of gelling or thickening agent

Q26. In vitro tape stripping is a technique used to assess:

• Microbial load on the product
• Drug penetration into layers of stratum corneum
• pH drift on the surface
• Viscosity under shear

Correct Answer: Drug penetration into layers of stratum corneum

Q27. What does the term “syneresis” refer to in gels?

• Increase in viscosity on storage
• Separation of liquid from gel matrix (weeping)
• Formation of new drug
• Change in pH to acidic range

Correct Answer: Separation of liquid from gel matrix (weeping)

Q28. Which evaluation is important for semisolids intended for ophthalmic application?

• Occlusion factor only
• Sterility, pH compatibility and isotonicity
• Texture firmness for skin application
• Extrudability from a large industrial tube only

Correct Answer: Sterility, pH compatibility and isotonicity

Q29. Compatibility studies for semisolid packaging aim to detect:

• Drug–container interactions such as sorption, leaching or permeation
• Spreadability improvements over time
• Viscosity increase due to sunlight only
• pH values in the range 1–2

Correct Answer: Drug–container interactions such as sorption, leaching or permeation

Q30. Which parameter is directly assessed by performing a water wash-off test on semisolids?

• Antioxidant capacity
• Washability or retention on skin under aqueous conditions
• Particle size distribution
• pH stability under alkaline conditions

Correct Answer: Washability or retention on skin under aqueous conditions

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