Soft gelatin capsules (softgels) are versatile single-unit dosage forms with a soft, elastic gelatin shell encapsulating liquid, semi-solid or suspension fills. B.Pharm students must grasp formulation factors such as gelatin type, bloom strength, plasticizers (glycerin, sorbitol), moisture content, and fill compatibility, plus key manufacturing methods like rotary-die and plate processes. Critical quality attributes include seal integrity, dissolution, disintegration, microbial limits, and stability. Practical challenges include crosslinking, leaching, volatile fills, and process parameters (temperature, drying, cooling). This coverage emphasizes formulation, encapsulation equipment, in-process controls, and troubleshooting for compliant softgel production. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which plasticizer is most commonly used in soft gelatin capsule shells?
- Glycerin
- Polyethylene glycol 400
- Triethyl citrate
- Propylene glycol
Correct Answer: Glycerin
Q2. What is the typical target moisture content range for finished soft gelatin capsules?
- 1–3% (w/w)
- 6–13% (w/w)
- 20–30% (w/w)
- 35–45% (w/w)
Correct Answer: 6–13% (w/w)
Q3. What does “bloom strength” of gelatin measure?
- The gelatin’s color intensity
- The gelatin’s gel strength
- The gelatin’s moisture content
- The gelatin’s pH
Correct Answer: The gelatin’s gel strength
Q4. Which manufacturing process is widely used for continuous high-volume production of softgels?
- Rotary die process
- Lyophilization
- Direct compression
- Spray drying
Correct Answer: Rotary die process
Q5. What is the primary purpose of adding a plasticizer to gelatin for softgel shells?
- To increase melting point
- To reduce brittleness and increase flexibility
- To sterilize the shell
- To accelerate drug release
Correct Answer: To reduce brittleness and increase flexibility
Q6. Which routine test is commonly used to detect leakage in soft gelatin capsules?
- Dissolution test
- Dye penetration test
- Friability test
- Disintegration test
Correct Answer: Dye penetration test
Q7. Reaction of gelatin with aldehyde-containing compounds typically causes which problem?
- Crosslinking leading to hardening of the shell
- Immediate shell dissolution
- Increased shell flexibility
- No effect on shell properties
Correct Answer: Crosslinking leading to hardening of the shell
Q8. Softgel fills are most compatible when the fill pH is maintained near which range?
- pH 1.0–2.5
- pH 3.0–4.0
- Around pH 4.5–7.5
- pH 9.0–11.0
Correct Answer: Around pH 4.5–7.5
Q9. Which combination of plasticizers is often used to optimize shell flexibility and reduce tack?
- Glycerin–sorbitol mixture
- PEG 400–triethyl citrate mixture
- Propylene glycol–isopropyl myristate
- Water–ethanol mixture
Correct Answer: Glycerin–sorbitol mixture
Q10. What is the primary objective of the controlled drying step after encapsulation?
- To sterilize the capsules
- To reduce shell moisture to target level
- To increase the bloom strength
- To remove plasticizer
Correct Answer: To reduce shell moisture to target level
Q11. Which laboratory finding typically indicates gelatin crosslinking in softgel shells?
- Increased resistance to pepsin digestion and failed dissolution
- Marked decrease in shell moisture immediately after encapsulation
- Increased solubility in water
- Lower bloom strength
Correct Answer: Increased resistance to pepsin digestion and failed dissolution
Q12. Which parameter primarily determines the external size of a softgel?
- Fill volume
- Gelatin bloom strength
- Ambient room humidity
- Drying time
Correct Answer: Fill volume
Q13. Which type of fill formulation is least suitable for direct encapsulation in standard soft gelatin shells?
- Aqueous solutions
- Oily solutions
- Non-aqueous suspensions
- Self-emulsifying drug delivery systems (SEDDS)
Correct Answer: Aqueous solutions
Q14. Which piece of equipment simultaneously forms the gelatin shell and deposits the fill during continuous softgel production?
- Rotary die encapsulation machine
- Fluid bed granulator
- Tablet press
- Coating pan
Correct Answer: Rotary die encapsulation machine
Q15. Why are surfactants included in some softgel fills?
- To act as the main plasticizer for the shell
- To impart color to the fill
- To improve emulsification and stability of the fill
- To increase capsule melting point
Correct Answer: To improve emulsification and stability of the fill
Q16. Which property of gelatin makes microbial control important during softgel manufacture?
- High proteinaceous nutrient content supporting microbial growth
- Inherent bactericidal activity
- Extremely low water activity
- Strong acidity
Correct Answer: High proteinaceous nutrient content supporting microbial growth
Q17. What is a typical temperature range for the gelatin mass during encapsulation?
- 20–30°C
- 40–50°C
- 60–65°C
- 90–100°C
Correct Answer: 60–65°C
Q18. What is the main purpose of cooling at the die roll area during rotary die encapsulation?
- To sterilize the capsule surface
- To solidify the shell and ensure proper sealing
- To remove plasticizer from the shell
- To increase fill viscosity
Correct Answer: To solidify the shell and ensure proper sealing
Q19. Which preservative is commonly used for aqueous softgel fills or aqueous-based gels?
- Methylparaben
- BHT (butylated hydroxytoluene)
- EDTA
- Ascorbic acid
Correct Answer: Methylparaben
Q20. A higher bloom value for gelatin generally indicates what property?
- Lower gel strength
- Stronger gel and higher gel melting point
- Greater moisture content
- Lower susceptibility to crosslinking
Correct Answer: Stronger gel and higher gel melting point
Q21. What is a common effect of overdrying soft gelatin capsules?
- Increased flexibility and reduced brittleness
- Brittle shells that crack or fracture
- Enhanced seal integrity
- Accelerated drug release
Correct Answer: Brittle shells that crack or fracture
Q22. Which QC method is used to detect leakers by creating pressure differential and observing failures?
- Vacuum tumble test
- Friability testing
- Water activity measurement
- pH testing
Correct Answer: Vacuum tumble test
Q23. Which coating technique is appropriate to apply an enteric coat to softgels?
- Fluid-bed coating with appropriate enteric polymer
- Compression coating
- Electroplating
- Lyophilization
Correct Answer: Fluid-bed coating with appropriate enteric polymer
Q24. Which polymer is commonly used as a vegetarian alternative to gelatin for soft capsules?
- Hydroxypropyl methylcellulose (HPMC)
- Polyvinyl chloride (PVC)
- Polyvinylpyrrolidone (PVP)
- Polyethylene (PE)
Correct Answer: Hydroxypropyl methylcellulose (HPMC)
Q25. Gelatin used in softgel shells is primarily derived from which source?
- Animal collagen (bovine/porcine)
- Plant cellulose
- Bacterial fermentation
- Synthetic polymers
Correct Answer: Animal collagen (bovine/porcine)
Q26. What is a frequent cause of capsules sticking together during production?
- High humidity or insufficient cooling leading to tacky shells
- Excessive freeze-drying
- Low fill viscosity
- Excessive bloom strength only
Correct Answer: High humidity or insufficient cooling leading to tacky shells
Q27. In softgel quality control terminology, what is a “leaker”?
- A capsule with a defective seal allowing leakage of the fill
- An oversized capsule beyond specification
- A capsule with excessively high moisture
- A discolored but intact capsule
Correct Answer: A capsule with a defective seal allowing leakage of the fill
Q28. Which test directly assesses the release rate of active drug from a softgel?
- Dissolution test
- Friability test
- Melting point determination
- Hardness test
Correct Answer: Dissolution test
Q29. Which analytical technique is most suitable for assay and content uniformity of drug in softgel fills?
- High-performance liquid chromatography (HPLC)
- Thin layer chromatography (TLC)
- Simple visual inspection
- Gravimetric analysis only
Correct Answer: High-performance liquid chromatography (HPLC)
Q30. Which contaminant is a well-known cause of gelatin crosslinking in capsules?
- Formaldehyde
- Glycerin
- Sodium chloride
- Sorbitol
Correct Answer: Formaldehyde
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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