Cold cream formulation MCQs With Answer

Cold cream formulation MCQs With Answer

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Cold cream formulation MCQs With Answer

This quiz set is designed for M.Pharm students studying Cosmetics & Cosmeceuticals (MPH 204T) and focuses on cold cream formulation, theory and quality control. It covers principles of water-in-oil emulsions, ingredient roles (oils, waxes, emulsifiers, preservatives), manufacturing operations, stability and evaluation tests, and regulatory/clinical considerations. Questions go beyond basic definitions to probe HLB requirements, emulsifier chemistry (e.g., borax-beeswax systems), rheology and sensory attributes, microbial control in low-water systems, and packaging influences on shelf life. Use these MCQs to consolidate formulation strategy, troubleshooting and QC approaches for developing safe, effective cold creams in a pharmaceutical setting.

Q1. Which emulsion type characterizes a traditional cold cream?

  • Oil-in-water (O/W) emulsion
  • Water-in-oil (W/O) emulsion
  • Suspension
  • Microemulsion

Correct Answer: Water-in-oil (W/O) emulsion

Q2. In classical cold cream formulations, what is the principal role of beeswax?

  • Primary preservative to inhibit microbial growth
  • Oil-phase thickener and emulsion stabilizer providing consistency
  • pH adjuster to maintain skin-friendly acidity
  • Humectant to increase water binding

Correct Answer: Oil-phase thickener and emulsion stabilizer providing consistency

Q3. Borax (sodium borate) is historically added to cold cream primarily to:

  • Act as an antioxidant preventing rancidity
  • React with fatty acids to form a soap-type emulsifier
  • Lower the final product pH below 4
  • Serve as a humectant to retain moisture

Correct Answer: React with fatty acids to form a soap-type emulsifier

Q4. For stable water-in-oil emulsions like cold creams, which HLB range is most suitable for the emulsifying system?

  • 8–12 (hydrophilic)
  • 10–18 (very hydrophilic)
  • 3–6 (lipophilic)
  • 15–20 (strongly hydrophilic)

Correct Answer: 3–6 (lipophilic)

Q5. Which ingredient is commonly used as a modern substitute for spermaceti in cold cream formulations?

  • Cetyl alcohol or cetyl palmitate
  • Sodium lauryl sulfate
  • Propylene glycol
  • Polyacrylic acid

Correct Answer: Cetyl alcohol or cetyl palmitate

Q6. Why do cold creams often show lower microbial proliferation compared to O/W creams?

  • They contain higher water activity promoting osmotic inhibition
  • The continuous oil phase limits water accessibility for microbes
  • They always contain stronger preservatives at high concentrations
  • Their pH is universally below 3, inhibiting growth

Correct Answer: The continuous oil phase limits water accessibility for microbes

Q7. What is a common in-process critical control point when manufacturing a cold cream?

  • Adding perfume before emulsification to ensure distribution
  • Maintaining oil and water phases at appropriate and uniform temperatures during mixing
  • Minimizing shear to avoid any emulsification
  • Evaporating the water phase completely

Correct Answer: Maintaining oil and water phases at appropriate and uniform temperatures during mixing

Q8. Which test best evaluates the mechanical stability of a cold cream under accelerated conditions?

  • pH titration
  • Freeze-thaw cycling and centrifugation
  • Viscosity only at ambient temperature
  • Odor panel testing

Correct Answer: Freeze-thaw cycling and centrifugation

Q9. The primary sensory attribute improved by using light liquid paraffin (mineral oil) in cold cream is:

  • Antimicrobial efficacy
  • Non-greasy, fast-absorbing feel
  • High comedogenicity for occlusion
  • Increased pH stability

Correct Answer: Non-greasy, fast-absorbing feel

Q10. Which preservative strategy is most appropriate for cold creams with limited aqueous phase?

  • No preservative is required due to low water content
  • Use of lipophilic preservatives and/or water-activity control plus broad‑spectrum preservatives
  • Rely solely on pH adjustment to 2.0 for preservation
  • High levels of simple sugars to inhibit microbes

Correct Answer: Use of lipophilic preservatives and/or water-activity control plus broad‑spectrum preservatives

Q11. Spreadability and consistency of a cold cream are commonly adjusted by varying which component?

  • Concentration and type of waxes and fatty alcohols
  • Quantity of preservative only
  • Amount of perfume
  • pH to extreme acidic values

Correct Answer: Concentration and type of waxes and fatty alcohols

Q12. A formulator observes rancid odor in a cold cream during stability testing. The most appropriate initial corrective measure is to:

  • Add a chelating agent and lipophilic antioxidant such as BHT or tocopherol
  • Increase the water content to dilute the oil
  • Raise pH to above 9
  • Eliminate all waxes from the formulation

Correct Answer: Add a chelating agent and lipophilic antioxidant such as BHT or tocopherol

Q13. Which in-vitro test helps quantify the occlusive property of a cold cream?

  • Trans-epidermal water loss (TEWL) measurement
  • UV-Vis spectroscopy of the cream
  • pH measurement only
  • Particle size analysis of the oil droplets

Correct Answer: Trans-epidermal water loss (TEWL) measurement

Q14. In a borax-beeswax cold cream system, what chemical interaction forms the emulsifying species?

  • Borate reacts with water to form hydrogen peroxide
  • Borate salts react with free fatty acids to form borate soaps
  • Beeswax hydrolyzes to glycerol
  • Borax reduces oil viscosity chemically

Correct Answer: Borate salts react with free fatty acids to form borate soaps

Q15. Which packaging choice best preserves the stability of a cold cream containing volatile fragrances?

  • Clear glass jar with wide opening
  • Opaque airless pump or tube to minimize air exposure
  • Perforated cap jar to allow breathability
  • Open bowl to allow fragrance evaporation

Correct Answer: Opaque airless pump or tube to minimize air exposure

Q16. The ideal pH range for a cold cream to be skin-friendly and chemically stable is approximately:

  • 2.0–3.0
  • 4.5–6.5
  • 8.5–10.5
  • 11.0–12.5

Correct Answer: 4.5–6.5

Q17. Which rheological parameter is most relevant for predicting a cold cream’s spreadability and structural recovery after shear?

  • Melting point of beeswax only
  • Viscoelastic moduli (G’ and G”) and thixotropy
  • Optical rotation
  • Surface tension of pure oil

Correct Answer: Viscoelastic moduli (G’ and G”) and thixotropy

Q18. During QC, which microbial test is essential for finished cold cream despite low water content?

  • Total aerobic microbial count and absence of specified pathogens
  • Only yeast/mold testing is required
  • None — creams are exempt from microbiological testing
  • Endotoxin testing only

Correct Answer: Total aerobic microbial count and absence of specified pathogens

Q19. Replacing mineral oil with a higher polarity ester (e.g., isopropyl myristate) in a cold cream is most likely to:

  • Increase occlusiveness and decrease skin spreadability
  • Improve skin penetration and give a lighter skin feel
  • Prevent emulsification completely
  • Render the product completely water soluble

Correct Answer: Improve skin penetration and give a lighter skin feel

Q20. Which stability indicator specifically signals emulsion phase inversion or breakage in a cold cream?

  • Increase in perfume intensity only
  • Oil separation or clear aqueous layer formation
  • Higher viscosity without any visual changes
  • Decrease in pH by 0.1 units

Correct Answer: Oil separation or clear aqueous layer formation

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