Preparation of dentifrices and mouthwashes MCQs With Answer

Introduction: Preparation of dentifrices and mouthwashes MCQs With Answer is a focused question bank designed for M.Pharm students studying Herbal Cosmetics (MPG 204T). This set covers formulation science, selection of excipients, herbal actives, stability, compatibility, quality control tests, and clinical considerations specific to dentifrices and mouthrinses. Questions emphasize mechanistic understanding—abrasivity, surfactant interactions, antimicrobial preservation, alcohol effects, and herbal ingredient roles—preparing students for advanced exams and practical formulation challenges. Each MCQ includes concise options and the correct answer to help reinforce critical concepts used in R&D, quality assurance, and regulatory aspects of oral-care product development.

Q1. Which abrasive is most commonly used in modern dentifrices because of its good cleaning performance and low dentin abrasivity?

• Hydrated silica
• Sodium lauryl sulfate
• Sorbitol
• Sodium fluoride

Correct Answer: Hydrated silica

Q2. What is the primary function of a humectant in toothpaste formulations?

• To increase foaming during brushing
• To prevent drying and maintain paste consistency
• To act as the main abrasive
• To provide fluoride ion

Correct Answer: To prevent drying and maintain paste consistency

Q3. Which abrasive is incompatible with soluble fluoride sources because it reacts with fluoride to reduce bioavailable fluoride?

• Hydrated silica
• Calcium carbonate
• Alumina
• Dicalcium phosphate anhydrous

Correct Answer: Calcium carbonate

Q4. In dentifrice science, what does the acronym RDA stand for?

• Relative Dentin Abrasivity
• Relative Dental Activity
• Rheological Dental Assessment
• Relative Dentifrice Affinity

Correct Answer: Relative Dentin Abrasivity

Q5. What is the main role of a surfactant in a toothpaste formulation?

• To act as a preservative
• To lower surface tension and aid cleaning and foaming
• To increase fluoride ion retention
• To act as an abrasive

Correct Answer: To lower surface tension and aid cleaning and foaming

Q6. Which preservative is commonly used in aqueous herbal mouthwashes to control microbial growth?

• Methylparaben alone
• Sodium benzoate
• Propylene glycol as sole preservative
• Sorbitol as antimicrobial

Correct Answer: Sodium benzoate

Q7. The antimicrobial efficacy of chlorhexidine mouthwash can be reduced by which common toothpaste ingredient?

• Sodium lauryl sulfate
• Glycerin
• Hydrated silica
• Calcium carbonate

Correct Answer: Sodium lauryl sulfate

Q8. Why is ethanol often incorporated into essential-oil containing mouthwashes?

• To act solely as a sweetener
• To solubilize essential oils and act as a co‑solvent/preservative
• To neutralize fluoride
• To act as the primary foaming agent

Correct Answer: To solubilize essential oils and act as a co‑solvent/preservative

Q9. Which of the following herbal extracts is most widely reported for antimicrobial and anti‑inflammatory properties in oral-care formulations?

• Azadirachta indica (Neem)
• Wheat germ oil
• Corn oil
• Olive oil

Correct Answer: Azadirachta indica (Neem)

Q10. Which polymer is commonly used as a binder and thickening agent in toothpaste formulations to provide the desired rheology?

• Sodium carboxymethyl cellulose
• Polyethylene glycol 4000 as main binder
• Hydrated silica as thickener
• Menthol as polymeric binder

Correct Answer: Sodium carboxymethyl cellulose

Q11. What is the preferred pH range for maintaining fluoride stability and efficacy in most dentifrices?

• pH 3.0–4.5 (strongly acidic)
• pH 5.0–6.0 (slightly acidic)
• pH 7.0–8.0 (neutral to slightly alkaline)
• pH >9.0 (strongly alkaline)

Correct Answer: pH 7.0–8.0 (neutral to slightly alkaline)

Q12. Which class of agents is commonly incorporated into dentifrices to reduce calculus formation?

• Pyrophosphate salts
• Essential oils
• Nonvolatile oils
• High levels of simple sugars

Correct Answer: Pyrophosphate salts

Q13. Which laboratory assay is most commonly used to quantify the antimicrobial potency of a mouthwash against oral pathogens?

• Minimum inhibitory concentration (MIC) assay
• Viscosity measurement
• Rheological profile
• Organoleptic panel scoring

Correct Answer: Minimum inhibitory concentration (MIC) assay

Q14. Which surfactant is the most frequently used foaming agent in traditional toothpastes, despite potential compatibility issues with some actives?

• Sodium lauryl sulfate
• Xanthan gum
• Hydrated silica
• Sodium fluoride

Correct Answer: Sodium lauryl sulfate

Q15. Which component in mouthwash formulations is most associated with mucosal irritation and is therefore limited or avoided in sensitive‑mouth products?

• Ethanol (alcohol)
• Glycerin
• Sodium fluoride
• Water

Correct Answer: Ethanol (alcohol)

Q16. The standard laboratory method to determine dentifrice abrasivity (RDA) relies on which technique?

• Radioactive dentin abrasion method measuring loss of radioactivity
• Simple visual scoring of stained tooth models
• pH titration of the paste
• Measuring foam volume after brushing

Correct Answer: Radioactive dentin abrasion method measuring loss of radioactivity

Q17. Which compound is commonly used as a peroxide‑based whitening agent in oral-care products?

• Hydrogen peroxide
• Sodium benzoate
• Triclosan
• Xylitol

Correct Answer: Hydrogen peroxide

Q18. Which sweetening agent used in dentifrices is non‑cariogenic and has documented anti‑caries benefits?

• Sucrose
• Saccharin
• Xylitol
• Fructose

Correct Answer: Xylitol

Q19. For light‑sensitive herbal mouthwash formulations containing essential oils, which packaging material is preferred to minimize photo‑oxidation?

• Amber glass bottle
• Clear PET bottle
• Transparent PVC sachet
• Aluminum aerosol can

Correct Answer: Amber glass bottle

Q20. Which analytical parameter is most relevant for monitoring oxidative degradation of essential oils in mouthwash during stability testing?

• Peroxide value (measure of oxidative rancidity)
• Foam index
• pH alone
• Color measured by organoleptic panel only

Correct Answer: Peroxide value (measure of oxidative rancidity)

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