Effervescent powders MCQs With Answer

Effervescent powders MCQs With Answer provide targeted practice for B. Pharm students studying pharmaceutics and dosage form design. Effervescent powders are dry blends of acids (commonly citric and tartaric acid) and carbonates/bicarbonates (usually sodium bicarbonate) that release carbon dioxide on contact with water, enhancing dissolution, taste masking, and patient compliance. Key topics include formulation principles, acid–base stoichiometry, fusion and wet granulation methods, moisture control, particle size and flow, quality control (effervescence time, CO2 content, assay), stability, packaging in moisture-resistant containers, labeling, and clinical considerations such as sodium load and palatability. Mastering these concepts helps in designing stable, patient-friendly formulations. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What best defines an effervescent powder?

• A sterile, parenteral dry powder to be reconstituted with water
• A dry blend of acid(s) and carbonate/bicarbonate that releases CO2 in water
• A hygroscopic powder that absorbs moisture for sustained release
• A non-disintegrating oral powder intended to be swallowed dry

Correct Answer: A dry blend of acid(s) and carbonate/bicarbonate that releases CO2 in water

Q2. Which acids are most commonly used in effervescent powders?

• Citric acid and tartaric acid
• Benzoic acid and salicylic acid
• Acetic acid and lactic acid
• Fumaric acid and hydrochloric acid

Correct Answer: Citric acid and tartaric acid

Q3. The primary purpose of effervescence in these powders is to:

• Increase gastric retention time
• Improve taste and accelerate dissolution by CO2 release
• Reduce dose frequency by sustained release
• Enhance chemical stability against hydrolysis

Correct Answer: Improve taste and accelerate dissolution by CO2 release

Q4. In the fusion method of preparing effervescent powders, citric acid monohydrate is valuable because it:

• Acts as a desiccant within the granules
• Melts/release bound water to form a binding syrup on gentle heating
• Prevents any acid–base reaction during heating
• Raises the pH of the final solution

Correct Answer: Melts/release bound water to form a binding syrup on gentle heating

Q5. During wet granulation of effervescent powders, which granulating solvent is preferred to minimize premature reaction?

• Purified water
• Absolute ethanol or isopropanol used sparingly
• Glycerin
• Propylene glycol

Correct Answer: Absolute ethanol or isopropanol used sparingly

Q6. Why is a combination of citric acid and tartaric acid often used?

• To eliminate the need for sodium bicarbonate
• To reduce CO2 release and prevent foaming
• To balance mechanical properties: citric alone is sticky; tartaric alone gives fragile granules
• To create an alkaline final solution

Correct Answer: To balance mechanical properties: citric alone is sticky; tartaric alone gives fragile granules

Q7. If citric acid is the only acid used, how many moles of sodium bicarbonate are theoretically required per mole of citric acid?

• One mole
• Two moles
• Three moles
• Four moles

Correct Answer: Three moles

Q8. If tartaric acid is the only acid used, how many moles of sodium bicarbonate are required per mole of tartaric acid?

• One mole
• Two moles
• Three moles
• Four moles

Correct Answer: Two moles

Q9. The most appropriate packaging for effervescent powders is:

• Permeable paper wraps
• Unlined metal tins
• Moisture-resistant unit-dose sachets or tubes with desiccant
• Open-top plastic cups

Correct Answer: Moisture-resistant unit-dose sachets or tubes with desiccant

Q10. Which statement about moisture is correct for effervescent powders?

• Moisture is needed to maintain effervescence during storage
• Moisture ingress causes premature reaction and caking
• High humidity improves flow
• Moisture has no effect on stability

Correct Answer: Moisture ingress causes premature reaction and caking

Q11. Which base is most commonly used in effervescent formulations?

• Magnesium oxide
• Calcium carbonate
• Sodium bicarbonate
• Ammonium carbonate

Correct Answer: Sodium bicarbonate

Q12. What particle size characteristic is preferred to reduce dusting and segregation in effervescent powders?

• Very fine micronized powders
• Uniform coarse granules
• Nanosized particles
• Mixed fines and coarse without control

Correct Answer: Uniform coarse granules

Q13. A key in-process control to avoid premature reaction during drying is to:

• Use high-temperature open-pan drying
• Employ low-temperature or vacuum drying with minimal residence time
• Add extra water to displace CO2
• Dry in ambient humid air

Correct Answer: Employ low-temperature or vacuum drying with minimal residence time

Q14. Which quality control test directly evaluates the “fizzing” performance in water?

• Angle of repose
• Assay by HPLC
• Effervescence time (dispersion/disintegration time)
• Friability

Correct Answer: Effervescence time (dispersion/disintegration time)

Q15. Why is CO2 content important in effervescent products?

• It prevents oxidation by consuming oxygen
• It ensures adequate fizzing, taste masking, and rapid dissolution
• It sterilizes the solution
• It increases the shelf life by raising pH

Correct Answer: It ensures adequate fizzing, taste masking, and rapid dissolution

Q16. Which labeling statement is most appropriate for effervescent powders?

• “Swallow the powder dry.”
• “Dissolve in water before use.”
• “Administer via IV route only.”
• “Keep refrigerated and open.”

Correct Answer: “Dissolve in water before use.”

Q17. Which patient group requires caution due to the sodium content of many effervescent formulations?

• Patients on sodium-restricted diets
• Patients with iron deficiency
• Patients with lactose intolerance
• Pediatric patients only

Correct Answer: Patients on sodium-restricted diets

Q18. The pH of the final solution after dissolution of an effervescent powder is primarily determined by:

• The flavor used
• The acid-to-bicarbonate stoichiometric ratio
• The colorant concentration
• The container size

Correct Answer: The acid-to-bicarbonate stoichiometric ratio

Q19. Which excipient is commonly added in small amounts to improve flow of effervescent granules?

• Colloidal silicon dioxide
• Sodium lauryl sulfate
• Starch paste
• Polyethylene glycol 400

Correct Answer: Colloidal silicon dioxide

Q20. Which statement about heat during fusion granulation is correct?

• Excessive heat can cause loss of CO2 and degrade product performance
• High heat always improves binding without side effects
• CO2 is not affected by temperature
• Heating is unnecessary and avoided in fusion method

Correct Answer: Excessive heat can cause loss of CO2 and degrade product performance

Q21. Which is an advantage of effervescent powders as a dosage form?

• Inherent resistance to moisture
• Rapid dissolution and improved palatability
• Minimal packaging requirements
• Complete taste neutrality without flavoring

Correct Answer: Rapid dissolution and improved palatability

Q22. During formulation, which sweetener is preferable for moisture-sensitive effervescent powders?

• Mannitol
• Sucrose syrup
• Liquid glucose
• Polyethylene glycol

Correct Answer: Mannitol

Q23. Which statement about mixing is most appropriate for effervescent powders?

• Prolonged high-shear mixing in humid air is ideal
• Acids and bases should be dry, sieved, and blended quickly under low humidity
• Moistening during mixing prevents segregation
• Mixing order does not matter

Correct Answer: Acids and bases should be dry, sieved, and blended quickly under low humidity

Q24. Which of the following is a typical clinical use of effervescent powders?

• Topical antibiotic delivery
• Oral delivery of analgesics, antacids, or vitamins with improved taste
• Ophthalmic suspensions
• Intranasal vaccines

Correct Answer: Oral delivery of analgesics, antacids, or vitamins with improved taste

Q25. Which packaging practice best protects effervescent powders during shelf life?

• Use of paper sachets without lining
• Opaque, tight, moisture-proof packs with optional desiccant
• Vented caps to release CO2
• Storing with wetting agents

Correct Answer: Opaque, tight, moisture-proof packs with optional desiccant

Q26. Which statement about flavors for effervescent products is most accurate?

• Oil flavors are never used
• Flavors may be used and often benefit from encapsulation to reduce volatilization
• Flavors always increase stability
• Flavors determine stoichiometry

Correct Answer: Flavors may be used and often benefit from encapsulation to reduce volatilization

Q27. Which test helps ensure dose uniformity in effervescent powders?

• Content uniformity or blend uniformity testing
• Transparency test
• Viscosity test
• Pyrogen test

Correct Answer: Content uniformity or blend uniformity testing

Q28. Why are effervescent powders often well accepted in pediatrics?

• They require injections
• They taste bitter inherently
• Effervescence masks unpleasant tastes and allows easy swallowing as a solution
• They are always sugar-free

Correct Answer: Effervescence masks unpleasant tastes and allows easy swallowing as a solution

Q29. Which factor most commonly triggers premature effervescence during storage?

• Exposure to low temperature
• Presence of residual or absorbed moisture
• Use of volatile flavors
• Light exposure alone

Correct Answer: Presence of residual or absorbed moisture

Q30. During formulation optimization, if the reconstituted solution tastes too alkaline, what adjustment is most appropriate?

• Increase the proportion of acid relative to bicarbonate
• Add more sodium bicarbonate
• Reduce flavor concentration only
• Increase drying temperature

Correct Answer: Increase the proportion of acid relative to bicarbonate

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