Introduction: Soft gelatin capsules (softgels) are versatile oral dosage forms widely used in B. Pharm curricula and industry for delivering lipophilic and liquid drugs. They combine a gelatin-plasticizer shell with an oil-based or semi-solid fill to enhance solubility, bioavailability, and patient compliance. Key topics include shell composition, plasticizers, filling systems (rotary die, plate processes), stability issues such as moisture migration and leakage, dissolution and disintegration testing, compatibility of actives and excipients, and quality control parameters like seal strength and uniformity. Understanding formulation, manufacturing, and regulatory considerations is essential for rational design and scale-up. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary advantage of using soft gelatin capsules for poorly water‑soluble drugs?
- Improved taste masking compared to tablets
- Improved bioavailability of lipophilic drugs
- Enhanced moisture protection for hygroscopic solids
- Controlled-release over 24 hours without coating
Correct Answer: Improved bioavailability of lipophilic drugs
Q2. Which component is the main film-former in a standard soft gelatin capsule shell?
- Polyvinylpyrrolidone (PVP)
- Gelatin
- Hydroxypropyl methylcellulose (HPMC)
- Ethylcellulose
Correct Answer: Gelatin
Q3. Which plasticizer is commonly used in softgel shells to impart flexibility?
- Propylene glycol
- Glycerol
- Sodium lauryl sulfate
- Poloxamer 188
Correct Answer: Glycerol
Q4. The rotary die encapsulation process is characterized by:
- Continuous formation of shells and simultaneous filling
- Batch casting of two half-shells welded later
- Injection molding of preformed shells
- Extrusion of solid plugs into capsules
Correct Answer: Continuous formation of shells and simultaneous filling
Q5. Which fill form is most appropriate for softgels intended to deliver lipophilic vitamins?
- Aqueous solution
- Oil solution
- Dry powder
- Immediate-release tablet placed inside
Correct Answer: Oil solution
Q6. A major stability concern for soft gelatin capsules containing water-sensitive actives is:
- Photodegradation due to opaque shells
- Moisture migration between shell and fill
- Excessive crosslinking causing shell hardening
- Insufficient lubrication during punching
Correct Answer: Moisture migration between shell and fill
Q7. Shell crosslinking in gelatin is most often caused by which condition?
- Exposure to high humidity only
- Reaction with aldehydes or formaldehyde
- Excessive plasticizer concentration
- Freezing below −20 °C
Correct Answer: Reaction with aldehydes or formaldehyde
Q8. Which test is critical to assess the integrity of soft gelatin capsule seals?
- Dissolution profiling at 37 °C
- Seal strength (peel) testing
- Hardness testing using a tablet hardness tester
- Friability by tumbling
Correct Answer: Seal strength (peel) testing
Q9. For rapid release of a lipophilic drug from a softgel, formulators often:
- Use high molecular weight gelatin only
- Add surfactants or cosolvents to the fill
- Make the shell thicker to slow water ingress
- Encapsulate the drug as a dry powder
Correct Answer: Add surfactants or cosolvents to the fill
Q10. Which analytical method is routinely used to quantify drug content in soft gelatin capsule fills?
- Near-infrared surface scanning
- HPLC after extraction of the fill
- Light microscopy
- Thermogravimetric analysis (TGA)
Correct Answer: HPLC after extraction of the fill
Q11. Which excipient reduces migration of water from shell to fill by lowering water activity in the shell?
- Sorbitol
- Magnesium stearate
- Microcrystalline cellulose
- Silica gel
Correct Answer: Sorbitol
Q12. When scaling up softgel manufacturing, a critical parameter to monitor is:
- Ambient room color
- Gelatin melt viscosity and temperature control
- The pH of the filling oil
- Operator handwriting on logs
Correct Answer: Gelatin melt viscosity and temperature control
Q13. Enteric soft gelatin capsules are achieved by:
- Using acid-insoluble gelatin in the shell
- Coating softgels with an enteric polymer
- Formulating the fill with buffering salts only
- Using hard gelatin instead of soft gelatin
Correct Answer: Coating softgels with an enteric polymer
Q14. Which preservation concern applies specifically to aqueous or hydrophilic fills in softgels?
- Oxidative rancidity of oils
- Microbial growth and need for preservatives
- Migration of caffeine to the shell
- Photodegradation of gelatin
Correct Answer: Microbial growth and need for preservatives
Q15. To minimize leaching of volatile solvents from the fill into the shell, formulators should:
- Increase shell moisture content above 20%
- Select low-volatility cosolvents and optimize shell composition
- Store capsules at high temperature
- Add water to the fill to dilute solvents
Correct Answer: Select low-volatility cosolvents and optimize shell composition
Q16. A common cause of fill leakage in softgels is:
- Excessive shell elasticity due to too much plasticizer
- Poorly controlled encapsulation temperature leading to weak seals
- Use of oil-based fills instead of aqueous fills
- Packaging in blisters instead of bottles
Correct Answer: Poorly controlled encapsulation temperature leading to weak seals
Q17. Which of the following is an advantage of softgels over hard capsules?
- Better suitability for powdered dry blends
- Ability to encapsulate liquids and semi-solids easily
- Lower manufacturing complexity
- Superior chewability for pediatric dosing
Correct Answer: Ability to encapsulate liquids and semi-solids easily
Q18. For oxidizable actives, which excipient is commonly added to the fill to improve stability?
- Antioxidants such as tocopherols
- Surfactants such as SDS
- Chelating agents that supply metal ions
- Strong reducing agents like sodium borohydride
Correct Answer: Antioxidants such as tocopherols
Q19. Which ICH condition is typically used for accelerated stability testing of softgels?
- 5 °C ± 3 °C and 15% RH
- 25 °C/60% RH
- 40 °C/75% RH
- 50 °C/95% RH
Correct Answer: 40 °C/75% RH
Q20. The term “over‑encapsulation” in softgel context most nearly refers to:
- Using an extra coating layer to mask taste
- Placing a softgel inside a hard shell for clinical blinding
- Filling a capsule beyond its nominal weight limit
- Encapsulating two actives in separate compartments
Correct Answer: Placing a softgel inside a hard shell for clinical blinding
Q21. Which quality control test specifically evaluates the uniformity of fill weight in softgels?
- Disintegration test
- Weight variation (individual fill weight) test
- Microbial limits test
- pH measurement of the shell
Correct Answer: Weight variation (individual fill weight) test
Q22. Plasticizer concentration in the shell affects which of the following properties most directly?
- Drug assay by HPLC
- Shell flexibility and brittleness
- Color of the fill
- Dissolution medium pH
Correct Answer: Shell flexibility and brittleness
Q23. Softgels are particularly useful for delivering which dosage form modification?
- Immediate-release matrix tablets
- Liquid self-emulsifying drug delivery systems (SEDDS)
- Gas-filled aerated solids
- Transdermal patches
Correct Answer: Liquid self-emulsifying drug delivery systems (SEDDS)
Q24. Which packaging condition best preserves softgel quality during storage?
- High humidity and direct sunlight exposure
- Desiccant-containing, light-protective primary packaging at controlled humidity
- Open trays at room humidity
- Refrigeration at −80 °C
Correct Answer: Desiccant-containing, light-protective primary packaging at controlled humidity
Q25. Which attribute is measured by dissolution testing of soft gelatin capsules?
- Shell color uniformity
- Rate and extent of drug release into medium
- Microbial bioburden
- Surface roughness
Correct Answer: Rate and extent of drug release into medium
Q26. To prevent catalytic degradation of an active in the fill, formulators may:
- Add trace metal catalysts to speed reaction
- Include chelating agents to sequester metal ions
- Increase exposure to oxygen
- Use reactive aldehyde-based preservatives
Correct Answer: Include chelating agents to sequester metal ions
Q27. Which property of the fill influences capsule shell moisture uptake most directly?
- Fill color
- Water activity of the fill
- Fill viscosity at 20 °C only
- Particle size distribution of solids
Correct Answer: Water activity of the fill
Q28. For bioavailability improvement using softgels, formulators often choose which strategy?
- Convert drug to a crystalline insoluble form
- Formulate as an oil-based solution or SEDDS
- Reduce surface area by compressing into pellets
- Increase shell thickness to delay release
Correct Answer: Formulate as an oil-based solution or SEDDS
Q29. Which regulatory document section is most relevant when validating softgel manufacturing processes?
- Label font specifications
- Good Manufacturing Practice (GMP) guidelines and process validation chapters
- Over-the-counter advertising rules
- Clinical trial informed consent templates
Correct Answer: Good Manufacturing Practice (GMP) guidelines and process validation chapters
Q30. When evaluating compatibility between fill and shell, which analytical approach is commonly used?
- Accelerated migration studies and chemical stability testing
- Only organoleptic (taste/smell) evaluation
- Measuring shell thickness with a caliper only
- Counting the number of softgels per blister
Correct Answer: Accelerated migration studies and chemical stability testing
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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