Ointment preparation is a core practical topic for B.Pharm students, covering ointment bases, manufacturing methods and evaluation parameters. Key concepts include fusion, levigation, incorporation and emulsification techniques, choice of oleaginous or water-washable bases, and use of humectants, preservatives and penetration enhancers. Evaluation focuses on rheology, spreadability, homogeneity, drug content, microbial limits, pH, in vitro release and accelerated stability testing. Understanding formulation principles, HLB considerations for emulsifiers, sterilization and GMP aspects ensures safe, effective topical products. This concentrated overview equips you to design, prepare and critically evaluate ointments in industry and research. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which method is most suitable for preparing ointments containing heat-sensitive drugs?
- Fusion method with prolonged heating
- Incorporation by geometric dilution at room temperature
- Hot emulsification followed by cooling
- Homogenization at high temperature
Correct Answer: Incorporation by geometric dilution at room temperature
Q2. Levigation in ointment preparation primarily serves to:
- Increase the melting point of the base
- Reduce particle size and improve smoothness
- Sterilize the active ingredient
- Create an emulsion with aqueous phase
Correct Answer: Reduce particle size and improve smoothness
Q3. Which ointment base is classified as water-removable (washable) base?
- Petrolatum
- Anhydrous lanolin
- Hydrophilic ointment (e.g., polyethylene glycol based)
- Emulsifying ointment (oil-in-water)
Correct Answer: Emulsifying ointment (oil-in-water)
Q4. The fusion method involves which principal step?
- Trituration of solid drug in a mortar with spatula
- Melting and mixing of base components followed by cooling
- Direct incorporation of powders into solid base at room temperature
- Spray-drying of ingredients to form a paste
Correct Answer: Melting and mixing of base components followed by cooling
Q5. Which parameter best assesses the ease of application of an ointment on skin?
- Viscosity only
- Spreadability
- pH
- Water activity
Correct Answer: Spreadability
Q6. For an oil-in-water ointment, which surfactant HLB is generally preferred for the emulsifier?
- HLB 3–6 (lipophilic)
- HLB 7–11 (intermediate)
- HLB 12–15 (hydrophilic)
- HLB 20–25 (highly hydrophilic)
Correct Answer: HLB 12–15 (hydrophilic)
Q7. Which evaluation test determines the uniform distribution of drug in an ointment batch?
- Spreadability test
- Homogeneity and content uniformity assay
- Pigment dispersion test
- pH measurement
Correct Answer: Homogeneity and content uniformity assay
Q8. Which preservative is commonly used in water-containing ointments?
- Propylparaben and methylparaben
- Petrolatum
- Lanolin
- Sorbitan monooleate
Correct Answer: Propylparaben and methylparaben
Q9. Which base would you select to maximize percutaneous absorption of a lipophilic drug?
- Polyethylene glycol (PEG) base
- White petrolatum (oleaginous) base
- Carbomer gel base
- Hydrophilic ointment (oil-in-water)
Correct Answer: White petrolatum (oleaginous) base
Q10. A critical advantage of water-soluble ointment bases (e.g., PEG) is:
- Non-washability from skin
- Compatibility with water-soluble drugs and easy wash-off
- Occlusive property to retain moisture
- High lipid content for deep penetration
Correct Answer: Compatibility with water-soluble drugs and easy wash-off
Q11. Which rheological property describes an ointment that becomes less viscous under shear?
- Thixotropy
- Rheopexy
- Newtonian behavior
- Plastic flow
Correct Answer: Thixotropy
Q12. Stability testing of ointments under accelerated conditions commonly uses which temperature?
- 5 ± 3 °C
- 25 ± 2 °C / 60% RH
- 40 ± 2 °C / 75% RH
- 100 °C constant
Correct Answer: 40 ± 2 °C / 75% RH
Q13. Which technique helps reduce air entrapment and produce a smooth ointment?
- Spatulation on an ointment slab with folding
- Vigorous high-speed heating
- Adding water to an oleaginous base
- Dry mixing powders without levigation
Correct Answer: Spatulation on an ointment slab with folding
Q14. Microbial quality of ointments is assessed by which test?
- pH determination
- Total viable aerobic count and absence of specified pathogens
- Viscosity measurement
- Spreadability index
Correct Answer: Total viable aerobic count and absence of specified pathogens
Q15. Which excipient acts as a penetration enhancer in topical ointments?
- Aquaphor
- Dimethyl sulfoxide (DMSO)
- Microcrystalline cellulose
- Glycerol monostearate
Correct Answer: Dimethyl sulfoxide (DMSO)
Q16. In ointment formulation, humectants are used to:
- Provide occlusion and prevent water loss
- Attract and retain moisture to the skin
- Increase the melting point of the base
- Promote microbial growth
Correct Answer: Attract and retain moisture to the skin
Q17. Which test measures the force required to spread an ointment between two glass plates?
- pH test
- Spreadability or extensibility test
- Thermal analysis
- Particle size distribution
Correct Answer: Spreadability or extensibility test
Q18. What is the main disadvantage of oleaginous ointment bases?
- Poor stability with lipophilic drugs
- They are easily washed off with water
- They are occlusive and non-washable, may cause greasiness
- They always require preservatives
Correct Answer: They are occlusive and non-washable, may cause greasiness
Q19. Which method is preferred to incorporate solid powders into a small amount of base evenly?
- Melt and pour method
- Geometric dilution
- Hot homogenization
- Freeze-drying
Correct Answer: Geometric dilution
Q20. Emulsifying ointment is an example of which type of base?
- Anhydrous oleaginous base
- Water-soluble base
- Water-removable (oil-in-water) base
- Water-immiscible gel
Correct Answer: Water-removable (oil-in-water) base
Q21. Which parameter is most relevant when assessing percutaneous drug delivery from an ointment?
- Organoleptic properties alone
- In vitro release/permeation studies across artificial membranes or skin
- Total volatile matter
- Color stability
Correct Answer: In vitro release/permeation studies across artificial membranes or skin
Q22. An ointment that displays yield value and flows only above a critical stress shows which flow behavior?
- Newtonian
- Plastic
- Thixotropic purely
- Viscoelastic solid
Correct Answer: Plastic
Q23. Which sterilization method is suitable for water-containing ointments sensitive to heat?
- Autoclaving at 121 °C
- Gamma irradiation or sterile filtration of aqueous phase before mixing
- Dry heat sterilization at 160 °C
- Boiling for 1 hour
Correct Answer: Gamma irradiation or sterile filtration of aqueous phase before mixing
Q24. A major quality concern when using natural lanolin in ointments is:
- Excessive hydrophilicity
- Potential for allergic reactions and variability
- Inability to incorporate lipophilic drugs
- Complete miscibility with petrolatum
Correct Answer: Potential for allergic reactions and variability
Q25. Which analytical test quantifies the active drug content in an ointment?
- Organoleptic assessment
- Assay by validated HPLC or UV method after suitable extraction
- Sensory panel testing
- Spreadability measurement
Correct Answer: Assay by validated HPLC or UV method after suitable extraction
Q26. In topical formulations, occlusion enhances percutaneous absorption primarily by:
- Removing all lipids from the stratum corneum
- Increasing skin hydration and swelling of stratum corneum
- Reducing drug partition coefficient
- Cooling the skin surface
Correct Answer: Increasing skin hydration and swelling of stratum corneum
Q27. Which excipient acts as an antioxidant in ointments to prevent rancidity of fatty bases?
- Ascorbic acid or butylated hydroxytoluene (BHT)
- Methylparaben
- Propylene glycol
- Carbomer
Correct Answer: Ascorbic acid or butylated hydroxytoluene (BHT)
Q28. During scale-up of ointment production, a common issue to monitor is:
- Color change only
- Reproducibility of mixing, heat transfer and homogeneity
- Only the raw material cost
- Replacing active ingredient with inert filler
Correct Answer: Reproducibility of mixing, heat transfer and homogeneity
Q29. Which property distinguishes a paste from an ointment?
- Paste contains a higher proportion of solids and is stiffer
- Paste is always water-soluble
- Ointments must be sterile but pastes do not
- Pastelike products are always liquid at room temperature
Correct Answer: Paste contains a higher proportion of solids and is stiffer
Q30. If an ointment’s in vitro release is too slow, a formulator may:
- Increase particle size of the drug
- Add a penetration enhancer or reduce base viscosity
- Remove preservative to speed release
- Decrease drug solubility in the base
Correct Answer: Add a penetration enhancer or reduce base viscosity
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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