Introduction
The formulation of liquid orals, especially syrups, is a core topic for B. Pharm students focused on dosage form design, excipient selection, and quality control. This introduction covers key concepts such as syrup vehicles, sweeteners, preservatives, viscosity modifiers, flavor masking, solubility enhancement, and stability considerations. Understanding formulation principles—choice of humectants, co-solvents, buffers, chelating agents, and antimicrobial preservatives—helps ensure patient acceptability, chemical and microbial stability, and accurate dosing. Practical topics include manufacturing methods, physicochemical tests (Brix, specific gravity, viscosity, pH), preservative efficacy, and regulatory expectations. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which component primarily imparts viscosity and mouthfeel to a syrup?
- Sugar (sucrose)
- Preservative
- Viscosity modifier (e.g., methylcellulose)
- Flavoring agent
Correct Answer: Viscosity modifier (e.g., methylcellulose)
Q2. Simple syrup USP is mainly composed of which concentration of sucrose in water?
- 10% w/v
- 50% w/v
- 85% w/v
- 100% w/v
Correct Answer: 85% w/v
Q3. Which preservative is commonly used in acidic syrups and is effective at low pH?
- Sodium benzoate
- Phenol
- Parabens (methylparaben)
- Sorbic acid
Correct Answer: Sodium benzoate
Q4. For sugar-free syrups, which sweetener is often used to provide bulk and sweetness?
- Glycerin
- Sodium chloride
- Sorbitol
- Calcium carbonate
Correct Answer: Sorbitol
Q5. Which test measures soluble solids in a syrup and is expressed in degrees?
- pH test
- Viscosity
- Brix (refractometry)
- Specific gravity
Correct Answer: Brix (refractometry)
Q6. Which excipient acts as a chelating agent to improve preservative efficacy in syrups?
- EDTA (ethylenediaminetetraacetic acid)
- Sucrose
- Methylparaben
- Glycerin
Correct Answer: EDTA (ethylenediaminetetraacetic acid)
Q7. Which manufacturing method involves heating to dissolve sugar and other solids in syrup preparation?
- Cold blending
- Fusion method
- Lyophilization
- Spray drying
Correct Answer: Fusion method
Q8. What is the primary reason for adding humectants like glycerin to syrups?
- To act as preservatives
- To increase sweetness intensity
- To retain moisture and prevent crystallization
- To reduce pH
Correct Answer: To retain moisture and prevent crystallization
Q9. Which parameter most directly affects microbial growth in syrups?
- Density
- pH and water activity
- Color
- Viscosity only
Correct Answer: pH and water activity
Q10. Which co-solvent is frequently used to increase solubility of poorly water-soluble drugs in syrups?
- Methanol
- Polyethylene glycol (PEG)
- Olive oil
- Liquid paraffin
Correct Answer: Polyethylene glycol (PEG)
Q11. Which preservative system is best suited for a syrup with neutral to slightly alkaline pH?
- Sodium benzoate alone
- Parabens (methylparaben/propylparaben)
- Sorbic acid alone
- Citric acid
Correct Answer: Parabens (methylparaben/propylparaben)
Q12. Which quality control test assesses flow resistance of a syrup?
- pH measurement
- Viscosity measurement (viscometer)
- Refractive index
- Disintegration test
Correct Answer: Viscosity measurement (viscometer)
Q13. Masking bitter taste in syrup formulations is primarily achieved by:
- Adding antioxidants
- Increasing preservative concentration
- Using flavors and sweeteners and ion-pairing or complexation
- Reducing viscosity
Correct Answer: Using flavors and sweeteners and ion-pairing or complexation
Q14. What is the purpose of adding antioxidants (e.g., sodium metabisulfite) in syrups?
- Prevent microbial growth
- Improve sweetness
- Prevent oxidative degradation of drug molecules
- Adjust viscosity
Correct Answer: Prevent oxidative degradation of drug molecules
Q15. Which packaging material is commonly preferred for syrups sensitive to light?
- Clear glass bottle
- Amber glass bottle
- Silver foil
- Cardboard box only
Correct Answer: Amber glass bottle
Q16. The preservative efficacy test (PET) in syrup quality control evaluates:
- Sweetness level
- Ability to resist microbial contamination over time
- Viscosity stability only
- Color stability in light
Correct Answer: Ability to resist microbial contamination over time
Q17. Which factor least affects the physical stability of a syrup?
- Temperature changes
- Light exposure
- Label print style
- pH variations
Correct Answer: Label print style
Q18. Which excipient acts both as a solvent and preservative enhancer by reducing water activity?
- Sucrose
- Glycerin
- Magnesium stearate
- Talc
Correct Answer: Glycerin
Q19. For syrups containing acid-labile drugs, which approach is most appropriate?
- Formulate at low pH
- Use buffering to neutral pH or include protective agents
- Increase sugar concentration only
- Avoid preservatives
Correct Answer: Use buffering to neutral pH or include protective agents
Q20. What is the main goal of flavor selection in pediatric syrups?
- Increase viscosity
- Enhance patient acceptability and compliance
- Reduce preservative potency
- Change drug pharmacokinetics
Correct Answer: Enhance patient acceptability and compliance
Q21. Which measurement gives the mass per unit volume of a syrup and is used in QC?
- pH
- Specific gravity
- Melting point
- Optical rotation
Correct Answer: Specific gravity
Q22. In syrups, sugar crystallization can be minimized by:
- Cooling rapidly without additives
- Adding invert sugar or glucose syrup and proper humectants
- Removing all humectants
- Exposing to light
Correct Answer: Adding invert sugar or glucose syrup and proper humectants
Q23. Which official compendium provides monographs and specifications for many syrups?
- International Building Code
- United States Pharmacopeia (USP)
- ISO 9001
- WHO Food Code
Correct Answer: United States Pharmacopeia (USP)
Q24. What is the typical role of citric acid in syrup formulations?
- Sweetener
- Surfactant
- pH adjuster and flavor enhancer
- Preservative only
Correct Answer: pH adjuster and flavor enhancer
Q25. Which problem is most likely if a syrup has insufficient preservative concentration?
- Excessive sweetness
- Microbial spoilage and contamination
- Higher viscosity
- Better flavor
Correct Answer: Microbial spoilage and contamination
Q26. Which technique helps assess chemical stability of drug in syrup during accelerated testing?
- Thermogravimetric analysis only
- Stability testing at elevated temperature and humidity with HPLC assay
- Visual color test only
- Density measurement only
Correct Answer: Stability testing at elevated temperature and humidity with HPLC assay
Q27. Which property of syrup affects dosing accuracy when using an oral measuring device?
- Color
- Viscosity
- Packaging label font
- Ambient odor
Correct Answer: Viscosity
Q28. Sorbitol and mannitol are primarily used in syrups as:
- Preservatives
- Bulking agents and non-cariogenic sweeteners
- Buffers
- Coatings
Correct Answer: Bulking agents and non-cariogenic sweeteners
Q29. In formulating a medicated syrup with a basic drug that forms salts, what must be considered?
- Only the color of the drug
- Drug solubility, pH, and possible salt formation affecting stability
- Ignore pH effects
- Preservative taste only
Correct Answer: Drug solubility, pH, and possible salt formation affecting stability
Q30. Which statement about antimicrobial preservatives in syrups is correct?
- They are effective regardless of pH and formulation components
- Their efficacy depends on pH, concentration, and interactions with other excipients
- They always increase drug potency
- They are unnecessary if sugar concentration is high
Correct Answer: Their efficacy depends on pH, concentration, and interactions with other excipients
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.
Mail- Sachin@pharmacyfreak.com