Introduction: Soft gelatin capsules are an important dosage form in B. Pharm curricula, focusing on capsule content, shell composition, formulation strategies, and stability. This topic covers fill materials (oils, solutions, suspensions), excipients (plasticizers, antioxidants, surfactants), shell ingredients (gelatin, plasticizers, colorants), manufacturing techniques (rotary die, dip-molding), and quality control (content uniformity, dissolution, leak testing). Understanding interactions, cross-linking, moisture effects, and analytical methods (HPLC, dissolution) is essential for formulation and stability assessment. These MCQs emphasize practical formulation decisions, common failure modes, and prevention strategies to prepare you for exams and industry practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which term best describes the material placed inside soft gelatin capsules?
- Shell matrix
- Fill material
- Binder solution
- Coating layer
Correct Answer: Fill material
Q2. What is the primary component of a soft gelatin capsule shell?
- Cellulose acetate
- Gelatin
- Polyethylene glycol
- Ethyl cellulose
Correct Answer: Gelatin
Q3. Which plasticizer is most commonly used in soft gelatin shells?
- Propylene glycol
- Glycerol
- Triethyl citrate
- Stearic acid
Correct Answer: Glycerol
Q4. Which vehicle is commonly used as a lipophilic fill for poorly water-soluble drugs in softgels?
- Medium-chain triglyceride (MCT) oil
- Povidone K30 aqueous solution
- Polyethylene glycol 400
- Glycerin aqueous blend
Correct Answer: Medium-chain triglyceride (MCT) oil
Q5. Which industrial process is most widely used for commercial soft gelatin capsule production?
- Rotary die process
- Spray drying
- Double emulsion
- Hot-melt extrusion
Correct Answer: Rotary die process
Q6. Which alternative manufacturing method involves gelatin ribbons formed by immersion/dip moulding?
- Rotary die filling
- Dip-moulding (plate process)
- Spray congealing
- Freeze drying
Correct Answer: Dip-moulding (plate process)
Q7. What is the primary purpose of adding a plasticizer to the gelatin shell?
- Increase drug solubility
- Enhance shell flexibility and prevent brittleness
- Act as a preservative
- Reduce fill viscosity
Correct Answer: Enhance shell flexibility and prevent brittleness
Q8. Gelatin cross-linking in shells typically causes which effect?
- Increased water solubility and faster dissolution
- Decreased solubility and slower dissolution
- Increased plasticity and elastic recovery
- Enhanced color stability
Correct Answer: Decreased solubility and slower dissolution
Q9. Which reactive compound is commonly implicated in promoting gelatin cross-linking?
- Sodium chloride
- Formaldehyde and other aldehydes
- Ascorbic acid
- Ethyl acetate
Correct Answer: Formaldehyde and other aldehydes
Q10. Soft gelatin capsules are most suitable for which class of drugs?
- Highly water-soluble ionic drugs
- Hydrophilic peptides only
- Lipophilic, poorly water-soluble drugs
- Gaseous APIs
Correct Answer: Lipophilic, poorly water-soluble drugs
Q11. Which quality control test directly assesses the amount of drug in each softgel?
- Disintegration test
- Weight variation only
- Content uniformity/assay
- Visual inspection
Correct Answer: Content uniformity/assay
Q12. Which simple test can detect ruptured or leaking softgel units?
- Dye penetration test
- pH paper test
- Friability tester
- Melting point determination
Correct Answer: Dye penetration test
Q13. Excessive environmental humidity primarily causes which problem in soft gelatin capsules?
- Increased shell brittleness and cracking
- Tacky surface, softening and deformation
- Loss of fill potency by evaporation
- Immediate drug precipitation inside fill
Correct Answer: Tacky surface, softening and deformation
Q14. Why are antioxidants added to oil-based fills in softgels?
- To increase shell hardness
- To prevent oxidative degradation of the drug or oil
- To act as flavoring agents
- To reduce fill viscosity
Correct Answer: To prevent oxidative degradation of the drug or oil
Q15. How are the two shell ribbons of a softgel sealed during manufacture?
- Cold adhesive bonding
- Thermal sealing/welding at the die
- Sonic welding after trimming
- Solvent evaporation sealing
Correct Answer: Thermal sealing/welding at the die
Q16. Which preservative is commonly used in gelatin shell formulations to control microbial growth?
- Methylparaben
- Citric acid only
- Magnesium stearate
- Calcium carbonate
Correct Answer: Methylparaben
Q17. Which storage condition is most likely to cause increased leakage and deformation of softgels?
- Low temperature refrigeration
- High temperature and high humidity
- Dry, cool environment
- Stable room temperature with desiccant
Correct Answer: High temperature and high humidity
Q18. What analytical technique is most appropriate for precise quantitation of drug in softgel fill during release and stability studies?
- Thin-layer chromatography (qualitative)
- High-performance liquid chromatography (HPLC)
- Visual color comparison
- Loss on drying
Correct Answer: High-performance liquid chromatography (HPLC)
Q19. What is the role of surfactants when included in a softgel fill?
- Increase shell bloom strength
- Improve drug solubility and dispersion in the vehicle
- Act as primary plasticizer for shell
- Prevent thermal sealing at the die
Correct Answer: Improve drug solubility and dispersion in the vehicle
Q20. Which Bloom strength of gelatin is commonly suitable for soft gelatin shells?
- 75 Bloom
- 125 Bloom
- 225 Bloom
- 350 Bloom
Correct Answer: 225 Bloom
Q21. Increasing glycerol concentration in the gelatin shell typically results in which effect?
- Decreased permeability
- Increased permeability
- Increased brittleness
- Higher melting point
Correct Answer: Increased permeability
Q22. A common cause of weld defects (cold joints) in softgel shells is:
- Excessive sealing temperature
- Insufficient heat or pressure during sealing
- Too high plasticizer concentration only
- Using medium-chain triglycerides as fill
Correct Answer: Insufficient heat or pressure during sealing
Q23. Typical moisture content range for soft gelatin shells to maintain flexibility and stability is:
- 0–1%
- 2–4%
- 6–12%
- 20–30%
Correct Answer: 6–12%
Q24. Which antioxidant is commonly used in oil-containing softgel fills to prevent lipid oxidation?
- Butylated hydroxytoluene (BHT)
- Sodium lauryl sulfate
- Sorbitol
- Hydrochloric acid
Correct Answer: Butylated hydroxytoluene (BHT)
Q25. For evaluation of drug release from soft gelatin capsules, which test is preferred?
- Melting point determination
- Dissolution testing
- Friability test
- pH meter check
Correct Answer: Dissolution testing
Q26. Which method is commonly used to measure the shell thickness of softgel capsules?
- Micrometer or optical microscopy
- pH titration
- Viscometry
- Gas chromatography
Correct Answer: Micrometer or optical microscopy
Q27. When formulating aqueous suspensions as softgel fills, what parameter is critical to control to avoid nozzle clogging and sedimentation?
- Particle size distribution
- Shell bloom strength
- Ambient humidity only
- Color of the suspension
Correct Answer: Particle size distribution
Q28. Gelatin is susceptible to hydrolysis under which pH conditions?
- Neutral pH only
- Moderately buffered pH
- Extreme pH: both strongly acidic and strongly alkaline
- Slightly alkaline pH only
Correct Answer: Extreme pH: both strongly acidic and strongly alkaline
Q29. Gelatin used for softgel shells is primarily derived from which natural source?
- Cellulose from plants
- Collagen from animal connective tissue
- Petroleum derivatives
- Synthetic polymers
Correct Answer: Collagen from animal connective tissue
Q30. Which primary packaging option best protects soft gelatin capsules from moisture and oxygen during storage?
- Open trays
- Aluminum-aluminum (Alu-Alu) blister packs with desiccant
- Perforated paper pouches
- Loose in cardboard boxes
Correct Answer: Aluminum-aluminum (Alu-Alu) blister packs with desiccant
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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