Wool fat (lanolin) is a complex, amphiphilic mixture of long-chain esters, free fatty acids, and steroidal alcohols obtained from the sebaceous secretions that coat sheep wool. For B.Pharm students, understanding its chemistry, sources, industrial preparation (scouring, solvent extraction, refining and fractionation), pharmacopoeial evaluation (acid value, saponification value, peroxide value, melting point, chromatographic profiling), preservation, storage, therapeutic uses (emollient, ointment base, transdermal enhancer, wound dressing) and commercial utility in cosmetics and pharmaceuticals is essential. Safety considerations include allergenicity, hydrogenation to reduce sensitizers, and appropriate antimicrobial preservation. This module links physicochemical properties to formulation performance and regulatory quality control. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which term is most synonymous with wool fat in pharmaceutical and cosmetic contexts?
- Lanolin
- Stearic acid
- Castor oil
- Beeswax
Correct Answer: Lanolin
Q2. Wool fat is primarily obtained from which part of the sheep?
- Milk glands
- Sebaceous secretions on wool
- Liver extracts
- Intestinal mucosa
Correct Answer: Sebaceous secretions on wool
Q3. The major chemical classes present in wool fat include which of the following?
- Long-chain esters, free fatty acids, and sterol alcohols
- Triglycerides only
- Short-chain ketones and aldehydes
- Polysaccharides and proteins
Correct Answer: Long-chain esters, free fatty acids, and sterol alcohols
Q4. Which processing step is typically used first to remove dirt and soluble impurities from raw wool before extracting wool fat?
- Hydrogenation
- Scouring (washing)
- Saponification
- Deodorization
Correct Answer: Scouring (washing)
Q5. A common industrial method to extract wool fat after scouring is:
- Steam distillation
- Cold pressing
- Solvent extraction using organic solvents
- Supercritical CO2 exclusively
Correct Answer: Solvent extraction using organic solvents
Q6. Which value is most useful to monitor hydrolytic degradation or free acid content in wool fat?
- Saponification value
- Acid value
- Iodine value
- Refractive index
Correct Answer: Acid value
Q7. The saponification value of wool fat primarily indicates the:
- Degree of unsaturation
- Average molecular weight of ester constituents
- Amount of free sterols
- Presence of peroxides
Correct Answer: Average molecular weight of ester constituents
Q8. Which test specifically measures the degree of oxidative rancidity in wool fat?
- Peroxide value
- Acid value
- Melting point
- pH measurement
Correct Answer: Peroxide value
Q9. Fractionation of wool fat is performed commercially to produce which two common grades?
- Anhydrous lanolin and hydrated lanolin
- Crude lanolin and stearic lanolin
- Hydrogenated lanolin and glyceryl lanolin
- Lanolin oleate and lanolin palmitate only
Correct Answer: Anhydrous lanolin and hydrated lanolin
Q10. Hydrogenation of wool fat is carried out mainly to:
- Increase its water content
- Reduce unsaturation and allergenic constituents
- Convert it into triglycerides
- Raise its acid value
Correct Answer: Reduce unsaturation and allergenic constituents
Q11. Which constituent of wool fat contributes most to its amphiphilic, emulsifying properties?
- Long-chain saturated hydrocarbons
- Sterol and alcohol esters
- Polysaccharides
- Free glycerol
Correct Answer: Sterol and alcohol esters
Q12. In formulation, wool fat functions primarily as a(n):
- Emollient and ointment base
- Antifungal active ingredient
- Hydrophilic surfactant
- Oral laxative
Correct Answer: Emollient and ointment base
Q13. Which pharmacopoeial parameter would be most relevant to ensure absence of strong oxidized by-products in lanolin?
- Peroxide value limit
- Viscosity at 40°C
- Colour tone grading
- Moisture content only
Correct Answer: Peroxide value limit
Q14. To reduce microbial contamination in stored wool fat, manufacturers often add:
- Antioxidants like BHT only
- Preservatives such as parabens or phenoxyethanol
- Calcium carbonate
- High concentrations of sucrose
Correct Answer: Preservatives such as parabens or phenoxyethanol
Q15. Which storage condition best preserves wool fat quality?
- Hot, humid, and exposed to light
- Cooled, dark, airtight containers
- Open containers at room light
- Under continuous aeration
Correct Answer: Cooled, dark, airtight containers
Q16. An adverse reaction to wool fat in a patient is most likely to be:
- Contact dermatitis (allergic reaction)
- Renal toxicity
- Immediate systemic anaphylaxis in all users
- Photosensitivity exclusively
Correct Answer: Contact dermatitis (allergic reaction)
Q17. Which analytical technique is commonly used to profile the molecular constituents of wool fat, including sterols and esters?
- Gas chromatography–mass spectrometry (GC-MS)
- Polarimetry only
- Thin-layer chromatography without detection
- Paper chromatography exclusively
Correct Answer: Gas chromatography–mass spectrometry (GC-MS)
Q18. The iodine value of wool fat gives information about its:
- Degree of unsaturation (double bonds)
- Acidity level
- Water-binding capacity
- Melting behavior only
Correct Answer: Degree of unsaturation (double bonds)
Q19. Which form of lanolin contains a controlled amount of combined water and is useful in certain ointments?
- Hydrated lanolin
- Anhydrous lanolin
- Hydrogenated anhydrous lanolin
- Crude wool grease
Correct Answer: Hydrated lanolin
Q20. When wool fat is saponified in a quality control test, the non-saponifiable fraction mainly contains:
- Sterols and alcohols
- Fatty acid salts exclusively
- Glycerol monoesters only
- Free inorganic salts
Correct Answer: Sterols and alcohols
Q21. Which commercial use of wool fat is most important in dermatological pharmaceuticals?
- As an emollient and ointment base to enhance skin hydration
- As an oral tablet binder
- As a systemic antibiotic
- As injectable vehicle for parenteral drugs
Correct Answer: As an emollient and ointment base to enhance skin hydration
Q22. To lower allergenicity, manufacturers may perform which of the following on lanolin?
- Hydrogenation and refined purification to reduce reactive components
- Addition of sulfuric acid without removal
- Heating with salt solely
- Mixing with crude wool grease
Correct Answer: Hydrogenation and refined purification to reduce reactive components
Q23. Which parameter helps determine the consistency and spreadability of wool fat products?
- Penetrometer or rheological measurements
- Chloride content
- Optical rotation only
- Boiling point
Correct Answer: Penetrometer or rheological measurements
Q24. In a transdermal formulation, lanolin can act as a penetration enhancer because it:
- Interacts with stratum corneum lipids to increase drug permeability
- Forms insoluble crystals on the skin surface exclusively
- Rapidly evaporates to leave drug behind
- Denatures proteins systemically
Correct Answer: Interacts with stratum corneum lipids to increase drug permeability
Q25. Which of the following is a major regulatory concern for commercial lanolin used in pharmaceuticals?
- Compliance with pharmacopoeial purity and microbial limits
- High caffeine content
- Radioactivity levels only
- Presence of synthetic polymers exclusively
Correct Answer: Compliance with pharmacopoeial purity and microbial limits
Q26. Deodorization and bleaching during lanolin processing are primarily performed to:
- Improve colour and odour for cosmetic acceptability
- Increase peroxide formation
- Raise water content above 10%
- Introduce fragrances into the core structure
Correct Answer: Improve colour and odour for cosmetic acceptability
Q27. Which preservative property is particularly important for lanolin used in water-containing ointments?
- Broad-spectrum antimicrobial activity
- High volatility
- Metal chelation only
- UV fluorescence
Correct Answer: Broad-spectrum antimicrobial activity
Q28. Which physical test can indicate the presence of water in an anhydrous lanolin sample?
- Loss on drying or Karl Fischer titration
- pH test only
- Boiling point elevation exclusively
- Optical density at 600 nm
Correct Answer: Loss on drying or Karl Fischer titration
Q29. Commercial utility of lanolin outside pharmaceuticals commonly includes:
- Cosmetics, leather conditioners, and corrosion inhibitors
- Fabric softener in powdered form only
- Primary ingredient in instant adhesives
- Food preservative for canned goods widely
Correct Answer: Cosmetics, leather conditioners, and corrosion inhibitors
Q30. During quality control, a significantly elevated acid value in a lanolin sample most likely indicates:
- Hydrolytic breakdown or fatty acid release
- Excessive hydrogenation
- High sterol purity
- Complete absence of free fatty acids
Correct Answer: Hydrolytic breakdown or fatty acid release
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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