Shampoo and toothpaste formulation MCQs With Answer

Shampoo and toothpaste formulation MCQs With Answer

This collection of MCQs is designed specifically for M.Pharm students studying Cosmetics & Cosmeceuticals (MPH 204T). The questions cover formulation principles, functional excipients, stability, safety, testing and regulatory aspects of shampoos and toothpastes. Emphasis is placed on mechanistic understanding — surfactant selection and behavior, rheology control, fluoride chemistry and abrasive compatibility, preservative strategies, and performance testing. Use these questions to test conceptual depth required at postgraduate level, identify knowledge gaps, and prepare for university exams or viva voce on topical formulation challenges encountered in modern hair and oral care product development.

Q1. Which class of surfactants is primarily responsible for high cleaning efficiency and strong foam in most commercial shampoos?

• Anionic surfactants such as sodium lauryl ether sulfate (SLES)
• Cationic surfactants such as cetyltrimethylammonium bromide
• Nonionic surfactants such as alkyl polyglucosides
• Silicone-based surfactants such as dimethicone copolyols

Correct Answer: Anionic surfactants such as sodium lauryl ether sulfate (SLES)

Q2. In SLES-based shampoo formulations, what is the typical effect of adding sodium chloride (salt) in moderate concentrations?

• Salt decreases viscosity and causes phase separation
• Salt increases viscosity up to an optimum concentration (salt-thickening)
• Salt converts SLES to a nonionic surfactant
• Salt acts as a preservative, increasing microbial stability

Correct Answer: Salt increases viscosity up to an optimum concentration (salt-thickening)

Q3. Which abrasive is commonly chosen for toothpaste formulations because it is compatible with fluoride and provides effective, low-abrasion cleaning?

• Calcium carbonate
• Dicalcium phosphate dihydrate
• Hydrated silica (amorphous silica)
• Aluminum oxide

Correct Answer: Hydrated silica (amorphous silica)

Q4. What is the primary therapeutic mechanism by which fluoride in toothpaste prevents dental caries?

• Neutralizes oral pH by buffering acids
• Acts as a desensitizing agent to block dentinal tubules
• Promotes remineralization and forms fluorapatite, reducing enamel solubility
• Serves as an abrasive to mechanically remove plaque

Correct Answer: Promotes remineralization and forms fluorapatite, reducing enamel solubility

Q5. For maximizing fluoride ion stability and bioavailability in sodium fluoride-containing toothpastes, what pH range is generally preferred?

• Strongly acidic (pH 3–4)
• Moderately acidic (pH 5–6)
• Neutral to slightly alkaline (pH 7–9)
• Strongly alkaline (pH 11–12)

Correct Answer: Neutral to slightly alkaline (pH 7–9)

Q6. Which amphoteric surfactant is widely used in shampoo formulations to reduce irritation and improve mildness while boosting foam stability?

• Sodium lauryl sulfate (SLS)
• Cocamidopropyl betaine
• Lauryl glucoside
• Polysorbate 20

Correct Answer: Cocamidopropyl betaine

Q7. Which class of polymers is commonly used as a conditioning agent in shampoos to reduce static and improve wet combing?

• Anionic polymers such as sodium polyacrylate
• Cationic polymers such as polyquaternium-10
• Nonionic cellulose ethers such as carboxymethylcellulose
• Silica-based rheology modifiers

Correct Answer: Cationic polymers such as polyquaternium-10

Q8. Which standardized test is used to evaluate the effectiveness of a preservative system in cosmetic formulations like shampoos and toothpastes?

• Skin irritation patch test
• Preservative Efficacy Test (PET) / Antimicrobial Effectiveness Test (USP)
• Biodegradability test
• Foam stability test

Correct Answer: Preservative Efficacy Test (PET) / Antimicrobial Effectiveness Test (USP)

Q9. Which humectant is most commonly used in toothpaste formulations to retain moisture and prevent drying of the paste?

• Isopropyl myristate
• Sorbitol
• Calcium carbonate
• Camphor

Correct Answer: Sorbitol

Q10. What is the standard laboratory index used to compare the relative abrasivity of toothpaste formulations on dentin?

• Foam Volume Index (FVI)
• Relative Dentin Abrasivity (RDA)
• Hydrophile-Lipophile Balance (HLB)
• Surface Roughness Coefficient (SRC)

Correct Answer: Relative Dentin Abrasivity (RDA)

Q11. Which surfactant is most associated with mucosal and skin irritation and is often reduced or replaced in “sensitive” personal care products?

• Disodium laureth sulfosuccinate
• Sodium lauryl sulfate (SLS)
• Cocamidopropyl hydroxysultaine
• Alkyl polyglucoside

Correct Answer: Sodium lauryl sulfate (SLS)

Q12. Which type of surfactant is frequently used in “tear-free” or baby shampoos because of its very mild irritation profile?

• Anionic sulfonates such as SLS
• Amphoteric betaines only
• Alkyl polyglucosides (APGs) — a nonionic, mild surfactant class
• Cationic quaternary ammonium surfactants

Correct Answer: Alkyl polyglucosides (APGs) — a nonionic, mild surfactant class

Q13. What is the principal function of chelating agents (e.g., EDTA) in shampoo and toothpaste formulations?

• Act as primary surfactants for cleaning
• Sequester divalent metal ions to prevent product destabilization and reduce staining
• Serve as abrasives for stain removal
• Provide flavor masking to the paste

Correct Answer: Sequester divalent metal ions to prevent product destabilization and reduce staining

Q14. In the HLB system used for emulsifier selection, what does a high HLB value (>10) generally indicate about the emulsifier’s preference?

• Preferential formation of water-in-oil (w/o) emulsions
• Preferential formation of oil-in-water (o/w) emulsions
• Strong antimicrobial activity
• High compatibility with anionic surfactants only

Correct Answer: Preferential formation of oil-in-water (o/w) emulsions

Q15. Which rheology modifier (gelling agent) is commonly used to produce clear, stable gels for shower gels and clear shampoo systems?

• Xanthan gum
• Carbomer (Carbopol)
• Microcrystalline cellulose
• Calcium carbonate

Correct Answer: Carbomer (Carbopol)

Q16. Which ingredient is commonly added to toothpaste formulations as an anti-foaming or defoaming agent to reduce excessive foam?

• Sodium lauryl sulfate (SLS)
• Dimethicone (silicone oil)
• Glycerin
• Sorbitol

Correct Answer: Dimethicone (silicone oil)

Q17. Which accelerated stability test involves subjecting shampoos or toothpastes to repeated cycles of heating and cooling to detect phase or rheology instability?

• Photostability testing under UV only
• Freeze–thaw cycling
• Fridge storage at 4 °C for 12 months
• Neutral pH challenge

Correct Answer: Freeze–thaw cycling

Q18. Which active ingredient is commonly incorporated into desensitizing toothpastes to reduce dentinal hypersensitivity by depolarizing nerve endings?

• Potassium nitrate
• Calcium carbonate
• Sodium lauryl sulfate
• Hydrated silica

Correct Answer: Potassium nitrate

Q19. What is the fundamental mechanism by which anionic surfactants remove sebum and oily soils from hair and skin?

• Forming ionic bridges that precipitate oils
• Creating micelles that solubilize and encapsulate oils for removal in rinse
• Reacting chemically with lipids to oxidize them
• Swelling hair fibers to mechanically dislodge oils

Correct Answer: Creating micelles that solubilize and encapsulate oils for removal in rinse

Q20. What is the commonly recommended fluoride concentration range (expressed as ppm fluoride) for adult over-the-counter toothpastes to provide anticaries efficacy?

• 100–250 ppm
• 500–750 ppm
• 1000–1500 ppm
• 2500–3500 ppm

Correct Answer: 1000–1500 ppm

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