Evaluation of semisolid dosage forms MCQs With Answer

Introduction: Evaluation of semisolid dosage forms MCQs With Answer provides B.Pharm students a focused review of methods used to assess creams, ointments, gels and pastes. This concise, keyword-rich introduction covers rheology, viscosity, spreadability, extrudability, drug content, in vitro release (Franz diffusion), preservative efficacy, microbial limits, stability testing (ICH), packaging compatibility and skin irritation assessment. Understanding these evaluation parameters is essential for formulation development, quality control and regulatory compliance in pharmaceutics. The questions emphasize practical tests, instruments (Brookfield, cone-plate), flow behavior (pseudoplastic, thixotropy), and interpretive criteria used in industry labs. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which test is commonly used to determine the in vitro release rate of a drug from a semisolid formulation?

• Franz diffusion cell method
• USP paddle dissolution for tablets
• Hot-stage microscopy
• Thermogravimetric analysis

Correct Answer: Franz diffusion cell method

Q2. Which rheological behavior is most desirable for a topical gel that should spread easily but remain on skin?

• Pseudoplastic (shear-thinning) with thixotropy
• Dilatant (shear-thickening)
• Newtonian with constant viscosity
• Highly plastic with no yield value

Correct Answer: Pseudoplastic (shear-thinning) with thixotropy

Q3. What parameter does spreadability testing primarily measure for semisolid formulations?

• Ease of application and area spread under defined force
• Chemical stability at elevated temperature
• Microbial contamination per gram
• Permeation through human skin in vivo

Correct Answer: Ease of application and area spread under defined force

Q4. Which instrument is widely used to measure viscosity of semisolid dosage forms in quality control?

• Brookfield viscometer
• Gas chromatograph
• UV-visible spectrophotometer
• Laser diffraction particle size analyzer

Correct Answer: Brookfield viscometer

Q5. What does extrudability testing assess for semisolid products packaged in tubes?

• Force required to expel product from the container
• Chemical compatibility with preservatives
• Drug assay accuracy by HPLC
• Skin sensitization potential

Correct Answer: Force required to expel product from the container

Q6. In semisolid evaluation, the term ‘occlusivity’ refers to:

• The ability of a formulation to prevent water loss from skin
• The antimicrobial preservative strength
• The electrical conductivity of the base
• The melting point of the vehicle

Correct Answer: The ability of a formulation to prevent water loss from skin

Q7. Which flow behavior is characterized by a yield value that must be exceeded before flow occurs?

• Plastic flow
• Pseudoplastic flow
• Newtonian flow
• Dilatant flow

Correct Answer: Plastic flow

Q8. The preservative efficacy test (challenge test) evaluates:

• Ability of formulation to reduce microbial load over time
• Stability of drug under light exposure
• Viscosity change with temperature
• Shelf-life by accelerated ICH conditions

Correct Answer: Ability of formulation to reduce microbial load over time

Q9. Which parameter is crucial to measure for water-containing semisolids to ensure microbial safety?

• Microbial limit test
• Melting point
• Oil phase refractive index
• Electrical resistance

Correct Answer: Microbial limit test

Q10. Which of the following is a common non-ionic emulsifying agent used in creams?

• Polysorbate 60 (Tween 60)
• Sodium lauryl sulfate
• Benzalkonium chloride
• Potassium sorbate

Correct Answer: Polysorbate 60 (Tween 60)

Q11. Why is pH measurement important for semisolid topical formulations?

• It affects drug stability, preservative efficacy and skin compatibility
• It determines the product’s color only
• It predicts packaging mechanical strength
• It measures particle size distribution

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

Q12. Which membrane is commonly used in Franz diffusion cells for semisolid release studies?

• Cellulose acetate membrane
• Polytetrafluoroethylene syringe filter
• Glass fiber filter for air sampling
• Metallic mesh

Correct Answer: Cellulose acetate membrane

Q13. In accelerated stability testing for semisolids, ICH conditions often use which temperature and humidity?

• 40°C and 75% RH
• 25°C and 30% RH
• 5°C and 20% RH
• 60°C and 95% RH

Correct Answer: 40°C and 75% RH

Q14. Which test determines the uniformity of drug content in a semisolid batch?

• Content homogeneity assay by sampling different portions
• Thermal gravimetric analysis
• Freeze–thaw cycling
• Viscoelastic frequency sweep

Correct Answer: Content homogeneity assay by sampling different portions

Q15. Thixotropy in semisolid formulations means:

• Viscosity decreases with time under constant shear and recovers on standing
• Viscosity increases with shear rate
• Viscosity remains constant regardless of shear
• The formulation hardens irreversibly on standing

Correct Answer: Viscosity decreases with time under constant shear and recovers on standing

Q16. Which test would best assess the irritancy potential of a topical semisolid?

• Patch test on human volunteers or validated animal model
• Determination of melting point
• Viscosity profiling
• Pyridine value determination

Correct Answer: Patch test on human volunteers or validated animal model

Q17. What is the main purpose of packaging compatibility studies for semisolid formulations?

• To ensure no interaction between formulation and container affects quality
• To measure the product’s osmolarity
• To determine the product’s refractive index
• To test tablet disintegration time

Correct Answer: To ensure no interaction between formulation and container affects quality

Q18. Which property is most relevant when evaluating ointment sticks?

• Hardness and melting point of the base
• Evaporation rate of volatile solvent only
• UV absorbance at 254 nm
• Electrical conductivity

Correct Answer: Hardness and melting point of the base

Q19. Which descriptor best fits a semisolid that becomes less viscous when stirred fast?

• Pseudoplastic or shear-thinning
• Dilatant or shear-thickening
• Newtonian
• Bingham plastic with infinite viscosity

Correct Answer: Pseudoplastic or shear-thinning

Q20. What is the significance of measuring particle size in medicated creams and gels?

• It affects drug release, stability and skin penetration
• It defines the product’s pH
• It measures preservative strength directly
• It indicates the color intensity only

Correct Answer: It affects drug release, stability and skin penetration

Q21. Which test assesses preservative effectiveness over specified time points after inoculation?

• Preservative efficacy test (PET) or challenge test
• In vitro diffusion test with Franz cell
• Spreadability under standardized weight
• Adhesion test to skin analog

Correct Answer: Preservative efficacy test (PET) or challenge test

Q22. What does the term ‘extrudability index’ reflect for creams in tubes?

• Relative force and ease of extrusion under standard conditions
• Degree of skin penetration in vivo
• Rate of microbial growth
• Melting range of the formulation

Correct Answer: Relative force and ease of extrusion under standard conditions

Q23. For semisolids, why is phase separation an important observation during stability studies?

• It indicates physical instability and loss of homogeneity
• It shows improved drug release
• It confirms microbial purity
• It measures pH stability only

Correct Answer: It indicates physical instability and loss of homogeneity

Q24. Which analytical method is commonly used to assay drug content in semisolids?

• HPLC (High-performance liquid chromatography)
• Nuclear magnetic resonance for routine QC
• Atomic absorption spectroscopy for organics
• Polarimetry for non-chiral drugs only

Correct Answer: HPLC (High-performance liquid chromatography)

Q25. What role does water activity play in semisolid formulations?

• Influences microbial growth potential and preservative performance
• Determines melting point of solid bases
• Measures the product’s viscosity directly
• Predicts color stability under light

Correct Answer: Influences microbial growth potential and preservative performance

Q26. Which of the following indicates a dilatant behavior in a semisolid?

• Viscosity increases with increasing shear rate
• Viscosity decreases with increasing shear rate
• Viscosity remains unchanged with shear
• The formulation liquefies on standing

Correct Answer: Viscosity increases with increasing shear rate

Q27. What is the primary objective of microbial limit tests for topical semisolids?

• To verify the product meets acceptable microbial counts and absence of specific pathogens
• To measure the preservative concentration chemically
• To evaluate viscosity change due to microbes
• To test the product’s physical color stability

Correct Answer: To verify the product meets acceptable microbial counts and absence of specific pathogens

Q28. Which test simulates repeated heating and cooling cycles to evaluate semisolid physical stability?

• Freeze–thaw cycling
• pH titration
• Karl Fischer titration
• Polarized light microscopy for crystals

Correct Answer: Freeze–thaw cycling

Q29. Why is rheological profiling important during formulation development of semisolids?

• It guides selection of bases and polymers to achieve desired application and stability
• It replaces the need for preservative testing
• It determines the chemical assay of active drug
• It only predicts packaging aesthetics

Correct Answer: It guides selection of bases and polymers to achieve desired application and stability

Q30. What is a common consequence of incompatible excipient–drug interaction in semisolids?

• Decreased drug potency and physical instability such as precipitation
• Increased viscosity without chemical change
• Improved preservative activity only
• Reduced pH without effect on drug stability

Correct Answer: Decreased drug potency and physical instability such as precipitation

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