Large-scale manufacturing of semisolid dosage forms MCQs With Answer

Introduction

This quiz set focuses on large-scale manufacturing of semisolid dosage forms and is designed for M.Pharm students preparing for advanced coursework and professional practice. Questions cover formulation approaches (gels, creams, ointments), process selection (fusion, high-shear mixing, homogenization), scale-up strategies, critical process parameters (CPPs) and critical quality attributes (CQAs), in-process controls, PAT applications, sterile and non-sterile considerations, cleaning and validation, packaging compatibility, and technology transfer challenges. The objective is to deepen understanding of practical manufacturing decisions, regulatory expectations and analytical methods used during development and commercial production of semisolid products.

Q1. Which statement best describes the fusion method commonly used in large-scale ointment and cream manufacture?

• The continuous addition of solid excipients to a cold vehicle without heating
• Heating both oil and aqueous phases separately to the same temperature, mixing, then cooling to form a semisolid
• High-pressure homogenization of a single-phase mixture at room temperature
• Direct dry blending of active and excipients followed by solvent evaporation

Correct Answer: Heating both oil and aqueous phases separately to the same temperature, mixing, then cooling to form a semisolid

Q2. Which property is considered a primary critical quality attribute (CQA) for semisolid topical products?

• Tablet hardness
• Rheological behavior (viscosity, thixotropy)
• Melting point of the API
• Coating thickness

Correct Answer: Rheological behavior (viscosity, thixotropy)

Q3. During scale-up of mixing for semisolids, which parameter is most often maintained to preserve mixing efficiency and shear history?

• Ambient room humidity
• Power input per unit volume (power/volume)
• Number of operator shifts
• Colour of mixing vessel

Correct Answer: Power input per unit volume (power/volume)

Q4. What is the principal purpose of high-shear homogenization in cream and emulsion manufacturing?

• Sterilize the product by heat generation
• Reduce droplet or particle size to improve emulsion stability and texture
• Increase bulk density of the formulation
• Remove volatile impurities by vacuum

Correct Answer: Reduce droplet or particle size to improve emulsion stability and texture

Q5. Which PAT (Process Analytical Technology) tool is commonly applied for real-time monitoring of content uniformity and moisture in semisolid production?

• Gas chromatography with flame ionization detector (GC-FID)
• Near-infrared (NIR) spectroscopy
• Ultraviolet-visible colorimetric strip test
• X-ray diffraction (XRD)

Correct Answer: Near-infrared (NIR) spectroscopy

Q6. What is the standard microbiological test used to evaluate preservative effectiveness in non-sterile semisolid products?

• Heavy metals limit test
• Preservative efficacy test (challenge test)
• Sterility test for aseptic products
• pH stability under accelerated conditions

Correct Answer: Preservative efficacy test (challenge test)

Q7. For accurate filling of high-viscosity ointments at commercial scale, which filling technology is most appropriate?

• Gravity-fed volumetric fillers
• Piston (positive displacement) fillers or progressive cavity pumps
• Spray atomisers
• Dropwise peristaltic filling without calibration

Correct Answer: Piston (positive displacement) fillers or progressive cavity pumps

Q8. During fusion and cooling of a crystalline ointment base, which process parameter strongly influences final microstructure and spreadability?

• Cooling rate and shear during solidification
• Ambient light intensity
• Container colour used for storage
• Operator clothing material

Correct Answer: Cooling rate and shear during solidification

Q9. Which instability mechanism is most characteristic of oil-in-water semisolid emulsions during shelf life?

• Polymer crosslinking
• Phase separation/coalescence leading to creaming
• Spontaneous sublimation of the oil phase
• Catalytic oxidation promoting gelling

Correct Answer: Phase separation/coalescence leading to creaming

Q10. Why is nitrogen blanketing often used on large mixing vessels for semisolid manufacture?

• To increase the product’s pH
• To prevent oxidative degradation and minimize oxygen-sensitive impurities
• To dissolve more solids into the formulation
• To sterilize the contents instantly

Correct Answer: To prevent oxidative degradation and minimize oxygen-sensitive impurities

Q11. For a non-sterile topical semisolid product, which microbial test is routinely performed as part of release testing?

• Endotoxin test by LAL
• Total aerobic microbial count (TAMC) and total yeast & mould count (TYMC)
• Sterility test according to USP sterility methods
• Viral plaque assay

Correct Answer: Total aerobic microbial count (TAMC) and total yeast & mould count (TYMC)

Q12. When producing sterile semisolid products containing heat-sensitive actives, the most appropriate manufacturing strategy is:

• Terminal steam sterilization of the filled product at 121°C
• Aseptic processing with sterile components and sterile filling
• Spray drying of the finished semisolid
• Gamma irradiation of the finished product in full containers without validation

Correct Answer: Aseptic processing with sterile components and sterile filling

Q13. The rheological term describing a formulation that recovers viscosity slowly after shear (time-dependent shear thinning) is:

• Newtonian flow
• Thixotropy
• Dilatancy
• Plastic flow with instant recovery

Correct Answer: Thixotropy

Q14. In topical semisolid formulations, what is the primary role of humectants such as glycerin?

• Act as primary emulsifiers for O/W emulsion
• Enhance water retention in the stratum corneum and prevent drying
• Promote rapid crystallization of the base
• Serve as preservatives against microbial growth

Correct Answer: Enhance water retention in the stratum corneum and prevent drying

Q15. Which study is essential to assess compatibility between a semisolid formulation and its primary packaging during product development?

• Extractables and leachables and stability interaction studies
• Tablet disintegration
• Particle size distribution by laser diffraction
• UV viscosity mapping of the container

Correct Answer: Extractables and leachables and stability interaction studies

Q16. During technology transfer of a semisolid product to a commercial site, which factor most frequently requires process re-optimization?

• Colour of the labels used
• Differences in equipment geometry and scale leading to altered mixing/shear
• Change in labeling font size
• Type of office chairs in the production office

Correct Answer: Differences in equipment geometry and scale leading to altered mixing/shear

Q17. Which gelling agent is commonly used for aqueous gel bases at production scale because of easy neutralization and strong thickening?

• Carbomer (polyacrylic acid)
• Calcium stearate
• Magnesium oxide
• Sodium chloride

Correct Answer: Carbomer (polyacrylic acid)

Q18. To preserve droplet size distribution when scaling up an emulsification step, manufacturers most often attempt to maintain which shear-related parameter?

• Tip speed or tip speed-related shear rate of the rotor/stator
• Number of operators present during blending
• Volume of headspace in the mixing vessel
• Colour of the mixing impeller

Correct Answer: Tip speed or tip speed-related shear rate of the rotor/stator

Q19. What is the primary goal of cleaning validation for semisolid manufacturing equipment?

• To ensure no microbial growth on the factory floor
• To demonstrate residues are removed to acceptable limits based on toxicological and analytical criteria
• To validate sterility of non-sterile products
• To sterilize personnel gloves

Correct Answer: To demonstrate residues are removed to acceptable limits based on toxicological and analytical criteria

Q20. Which in-process control provides the most direct information about batch-to-batch consistency of semisolid texture during manufacture?

• Viscosity or rheological measurement
• Colorimeter reading of packaging labels
• Ambient music choice in production area
• Number of boxes in finished goods warehouse

Correct Answer: Viscosity or rheological measurement

Download