Introduction: Benzyl benzoate structure and uses are essential topics for B. Pharm students studying pharmaceutical chemistry, formulation, and therapeutics. Benzyl benzoate is an aromatic ester (C14H12O2) formed from benzyl alcohol and benzoic acid; its molecular structure, physicochemical properties, and ester linkage determine solubility, volatility, and stability. Clinically, it serves as an effective scabicide and pediculicide, a solvent and preservative in topical formulations, and an excipient in parenteral preparations. Understanding its mechanism of action, pharmacokinetics, toxicity profile, assay methods, and regulatory standards is vital for safe formulation and patient care. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What is the chemical classification of benzyl benzoate?
- Aromatic ester
- Aliphatic alcohol
- Aromatic amide
- Carboxylic acid
Correct Answer: Aromatic ester
Q2. The structural formula of benzyl benzoate can be best described as:
- Benzyl group linked to benzoic acid via an ester bond
- Benzoic acid directly attached to a benzene ring without linkage
- Benzene ring with two hydroxyl groups
- A benzyl chloride derivative
Correct Answer: Benzyl group linked to benzoic acid via an ester bond
Q3. Which functional groups are present in benzyl benzoate?
- Ester and aromatic rings
- Alcohol and ketone
- Amine and amide
- Carboxylic acid and aldehyde
Correct Answer: Ester and aromatic rings
Q4. Benzyl benzoate is commonly used as which of the following in topical therapy?
- Scabicide and pediculicide
- Systemic antibiotic
- Antifungal for internal use
- Oral analgesic
Correct Answer: Scabicide and pediculicide
Q5. Which property makes benzyl benzoate useful as a solvent in pharmaceutical formulations?
- High lipophilicity and solvent power for lipophilic drugs
- Strong acidity
- High water solubility
- Reducing agent characteristics
Correct Answer: High lipophilicity and solvent power for lipophilic drugs
Q6. In synthesis, benzyl benzoate is formed by esterification of benzoic acid with:
- Benzyl alcohol
- Methanol
- Ethanol
- Benzene
Correct Answer: Benzyl alcohol
Q7. Which catalyst is commonly used in the laboratory Fischer esterification to make benzyl benzoate?
- Concentrated sulfuric acid
- Sodium hydroxide
- Palladium on carbon
- Sodium borohydride
Correct Answer: Concentrated sulfuric acid
Q8. The primary mechanism of action of benzyl benzoate against scabies mites is:
- Neurotoxicity to parasites via solvent-mediated disruption
- Inhibition of bacterial cell wall synthesis
- Blocking human acetylcholinesterase systemically
- Acting as an antifolate agent
Correct Answer: Neurotoxicity to parasites via solvent-mediated disruption
Q9. Which of the following describes the physical state of benzyl benzoate at room temperature?
- Viscous oily liquid
- White crystalline solid
- Colorless gas
- Powdery solid
Correct Answer: Viscous oily liquid
Q10. Which analytical method is most suitable for quantifying benzyl benzoate in formulations?
- Gas chromatography (GC) with flame ionization detection
- Colorimetry using ninhydrin
- Immunoassay
- Conductivity measurement
Correct Answer: Gas chromatography (GC) with flame ionization detection
Q11. What is a major metabolic pathway for benzyl benzoate in humans?
- Hydrolysis to benzyl alcohol and benzoic acid followed by conjugation
- Oxidative deamination to form aldehydes
- Direct excretion unchanged in urine
- Sulfation to form benzyl sulfate
Correct Answer: Hydrolysis to benzyl alcohol and benzoic acid followed by conjugation
Q12. Which conjugation reaction commonly follows metabolism of benzoic acid in humans?
- Glycine conjugation to form hippuric acid
- Glucuronidation to form sulfate conjugates
- Methylation to form methoxybenzoates
- Acetylation of benzoic acid
Correct Answer: Glycine conjugation to form hippuric acid
Q13. Which adverse effect is most commonly associated with topical benzyl benzoate?
- Skin irritation and stinging
- Severe systemic hypotension
- Renal failure
- Photosensitivity leading to systemic rash
Correct Answer: Skin irritation and stinging
Q14. For pediatric use, benzyl benzoate application should be:
- Used with caution and at reduced concentrations
- Given systemically by oral route
- Applied at the same adult concentration always
- Never used under any circumstance
Correct Answer: Used with caution and at reduced concentrations
Q15. Which statement about benzyl benzoate’s solubility is correct?
- Practically insoluble in water but miscible with organic solvents
- Highly soluble in water
- Soluble only in strong acids
- Soluble in saline but not in ethanol
Correct Answer: Practically insoluble in water but miscible with organic solvents
Q16. In formulation, benzyl benzoate may act as an excipient primarily as a:
- Solvent and penetration enhancer
- Bulking agent
- Alkalinizing agent
- Hydrophilic surfactant
Correct Answer: Solvent and penetration enhancer
Q17. Which compendial test is important for benzyl benzoate when used therapeutically?
- Assay of active ingredient purity by GC
- Determination of microbial endotoxins only
- Loss on drying for volatile acids
- Assay by titration with sodium hydroxide only
Correct Answer: Assay of active ingredient purity by GC
Q18. Which condition is a contraindication for benzyl benzoate topical use?
- Open or inflamed wounds where absorption increases
- Non-infected intact skin
- Mild dry skin with no lesions
- Use as a laundry additive
Correct Answer: Open or inflamed wounds where absorption increases
Q19. Stability of benzyl benzoate in formulations is primarily affected by:
- Hydrolysis under acidic or basic conditions
- Oxidative cleavage by ozone only
- Photodecarboxylation in the dark
- Polymerization at low pH
Correct Answer: Hydrolysis under acidic or basic conditions
Q20. Which packaging consideration is appropriate for benzyl benzoate-containing topical products?
- Use airtight, light-resistant containers to prevent degradation
- Store in open jars to allow evaporation
- Use metal containers that react with esters
- Store at high temperatures to maintain viscosity
Correct Answer: Use airtight, light-resistant containers to prevent degradation
Q21. Which instrumental method can distinguish benzyl benzoate from structurally similar esters?
- Gas chromatography-mass spectrometry (GC-MS)
- Simple UV-visible spectrophotometry at 260 nm
- Titration with potassium permanganate
- Paper chromatography under room light
Correct Answer: Gas chromatography-mass spectrometry (GC-MS)
Q22. Which of the following is a common formulation concentration of benzyl benzoate for scabies treatment?
- 25% topical lotion
- 0.1% oral solution
- 100% undiluted application
- 0.01% injectable
Correct Answer: 25% topical lotion
Q23. When performing an assay, benzyl benzoate gives a characteristic GC retention time due to:
- Its specific volatility and polarity
- Its ionic charge at neutral pH
- Its heavy metal content
- Its insolubility in organic solvents
Correct Answer: Its specific volatility and polarity
Q24. Which metabolite is commonly measured as a marker of benzoic acid metabolism?
- Hippuric acid in urine
- Benzoic amide in plasma
- Benzyl chloride in breath
- Toluene in blood
Correct Answer: Hippuric acid in urine
Q25. Incompatibility of benzyl benzoate with which excipient is a formulation concern?
- Strong bases that promote ester hydrolysis
- Neutral oils like mineral oil
- Inert fillers like lactose
- Non-ionic surfactants at low concentration
Correct Answer: Strong bases that promote ester hydrolysis
Q26. Which safety precaution is important for pharmacists compounding benzyl benzoate?
- Use gloves and avoid skin contact due to irritation risk
- Consume a small amount to test aroma
- Mix at high temperatures to speed reaction
- Use open bench without ventilation
Correct Answer: Use gloves and avoid skin contact due to irritation risk
Q27. The log P (octanol-water partition coefficient) of benzyl benzoate indicates it is:
- Highly lipophilic favoring skin penetration
- Highly hydrophilic and poorly permeable through skin
- Ionic at physiological pH
- Unable to partition into lipids
Correct Answer: Highly lipophilic favoring skin penetration
Q28. Environmental concern related to benzyl benzoate disposal includes:
- Potential toxicity to aquatic organisms
- Formation of ozone-depleting substances
- Rapid conversion to heavy metals
- Generation of radioactive waste
Correct Answer: Potential toxicity to aquatic organisms
Q29. Which derivative is produced by hydrogenation of benzyl benzoate?
- Benzyl cyclohexanecarboxylate (reduced aromatic ring)
- Benzoic acid (from simple oxidation)
- Benzyl chloride (from substitution)
- Benzoic anhydride (from dehydration)
Correct Answer: Benzyl cyclohexanecarboxylate (reduced aromatic ring)
Q30. Which regulatory specification is typically required for pharmaceutical-grade benzyl benzoate?
- Defined purity limits and impurity profile in pharmacopeia
- No specifications; any grade is acceptable
- Only odor testing is required
- Mandatory radiolabeling
Correct Answer: Defined purity limits and impurity profile in pharmacopeia
Q31. Which analytical parameter assesses benzyl benzoate’s volatility during storage?
- Boiling point and vapor pressure data
- pH of the sample
- Calorimetric melting point only
- Optical rotation
Correct Answer: Boiling point and vapor pressure data
Q32. Combining benzyl benzoate with permethrin in a topical formulation is intended to:
- Enhance antiparasitic efficacy by combined mechanisms
- Neutralize each other and reduce activity
- Make the product suitable for oral use
- Convert it into a systemic antibiotic
Correct Answer: Enhance antiparasitic efficacy by combined mechanisms
Q33. Which indicator of dermal absorption is important when evaluating benzyl benzoate safety?
- Skin permeability coefficient and area of application
- Boiling point of the topical vehicle
- Aroma threshold in air
- Color change on UV exposure
Correct Answer: Skin permeability coefficient and area of application
Q34. Benzyl benzoate’s role as a fragrance ingredient is based on:
- Characteristic balsamic sweet aroma
- Strong sulfurous odor
- Bitter taste when ingested
- High basicity
Correct Answer: Characteristic balsamic sweet aroma
Q35. Which storage temperature condition is recommended for maintaining benzyl benzoate stability?
- Cool, controlled room temperature away from heat sources
- High temperature to keep it fluid
- Below -20°C in cryogenic storage
- Continuous exposure to sunlight
Correct Answer: Cool, controlled room temperature away from heat sources
Q36. Which hazard classification applies to benzyl benzoate in Material Safety Data Sheets (MSDS)?
- Irritant to skin and eyes; avoid inhalation
- Explosive and highly flammable gas
- Radioactive material
- Non-hazardous with no precautions
Correct Answer: Irritant to skin and eyes; avoid inhalation
Q37. Which chromatographic stationary phase is suitable for GC separation of benzyl benzoate?
- Non-polar capillary column (e.g., DB-5)
- Strong cation exchange column
- Size-exclusion column packed with agarose
- Ion-pair HPLC column designed for proteins
Correct Answer: Non-polar capillary column (e.g., DB-5)
Q38. In quality control, an impurity of concern in benzyl benzoate might be:
- Unreacted benzyl alcohol
- Sodium chloride crystals
- Inorganic carbonates
- Cellulose fibers
Correct Answer: Unreacted benzyl alcohol
Q39. What is the reason benzyl benzoate is not suitable for systemic antibacterial therapy?
- Poor water solubility and limited systemic bioavailability
- It is a potent systemic antibiotic already
- It specifically targets viruses, not bacteria
- Its molecular weight is too low to be absorbed
Correct Answer: Poor water solubility and limited systemic bioavailability
Q40. Which reaction would hydrolyze benzyl benzoate back to benzoic acid and benzyl alcohol?
- Aqueous acid- or base-catalyzed hydrolysis
- Hydrogenation under mild conditions
- Photolytic aromatization
- Nucleophilic substitution with chloride ion
Correct Answer: Aqueous acid- or base-catalyzed hydrolysis
Q41. When testing formulation compatibility, which test should be performed for benzyl benzoate blends?
- Accelerated stability studies at elevated temperature and humidity
- Only smell testing for scent acceptability
- Immediate freeze-thaw without further analysis
- Only visual color check with no instrumentation
Correct Answer: Accelerated stability studies at elevated temperature and humidity
Q42. Which statement about benzyl benzoate’s antimicrobial activity is true?
- It has limited antibacterial activity; primarily antiparasitic topically
- It is a broad-spectrum systemic antibiotic
- It is an antifungal for oral candidiasis
- It is an antiviral agent used for influenza
Correct Answer: It has limited antibacterial activity; primarily antiparasitic topically
Q43. Which patient population requires extra caution when prescribing benzyl benzoate?
- Infants and very young children due to skin sensitivity
- Healthy adults with no skin disease
- Patients using only oral vitamins
- Individuals with intact non-irritated skin
Correct Answer: Infants and very young children due to skin sensitivity
Q44. Which in vitro test can estimate the percutaneous absorption of benzyl benzoate?
- Franz diffusion cell studies using human or animal skin
- Ambient air dispersion test
- pH titration of the formulation
- Osmolarity measurement
Correct Answer: Franz diffusion cell studies using human or animal skin
Q45. In industrial production, a green chemistry improvement for benzyl benzoate synthesis would be:
- Using catalytic esterification and solvent recycling to reduce waste
- Using large excesses of hazardous solvent without recovery
- Heating indefinitely without monitoring reaction progress
- Disposing of by-products untreated
Correct Answer: Using catalytic esterification and solvent recycling to reduce waste
Q46. Which spectroscopic technique can provide information about the ester carbonyl in benzyl benzoate?
- Infrared (IR) spectroscopy showing a C=O stretch around 1700 cm⁻¹
- Fluorescence spectroscopy only
- Near-infrared reflectance for ionic bonds
- Magnetic susceptibility measurements
Correct Answer: Infrared (IR) spectroscopy showing a C=O stretch around 1700 cm⁻¹
Q47. Which of the following interactions may increase systemic absorption of benzyl benzoate?
- Application on damaged or inflamed skin
- Applying to dry, intact skin only
- Using with a non-penetrating powder
- Applying in a single, limited spot
Correct Answer: Application on damaged or inflamed skin
Q48. For labeling, which patient instruction is critical for benzyl benzoate lotion?
- Apply as directed and avoid contact with eyes and mucous membranes
- Ingest a teaspoon daily with food
- Store in direct sunlight to activate the product
- Shake and heat before use
Correct Answer: Apply as directed and avoid contact with eyes and mucous membranes
Q49. Which is a common impurity arising from over-oxidation during benzyl benzoate manufacture?
- Benzoic acid
- Sodium benzoate crystals
- Polyethylene glycol
- Chitosan residues
Correct Answer: Benzoic acid
Q50. In a formulation containing benzyl benzoate, which evaluation ensures therapeutic performance?
- Bioequivalence of topical delivery and efficacy testing for antiparasitic action
- Only measuring odor profile
- Counting particulate matter without efficacy tests
- Ignoring stability and performing no testing
Correct Answer: Bioequivalence of topical delivery and efficacy testing for antiparasitic action
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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