Introduction: The morphological classification of drugs is a practical framework for B.Pharm students to understand pharmaceutical forms by their physical appearance, structure and delivery characteristics. This topic covers solid, liquid, semi-solid and gaseous dosage forms; concepts like particle size, crystal habit, polymorphism, hydrates/solvates, micromeritics, flow properties, and colloidal systems; and formulation-related terms such as excipients, coatings, emulsions, suspensions, transdermal systems and inhalation aerosols. Mastery of these keywords and principles links morphology to dissolution, stability, bioavailability and manufacturing behavior. Clear understanding helps in selection of dosage form, troubleshooting and quality control. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which classification method groups drugs primarily by their physical form, particle shape and dosage form?
- Chemical classification
- Therapeutic classification
- Pharmacokinetic classification
- Morphological classification
Correct Answer: Morphological classification
Q2. Which of the following is a solid dosage form commonly covered under morphological classification?
- Tablet
- Syrup
- Ointment
- Aerosol
Correct Answer: Tablet
Q3. Polymorphism in drug substances refers to:
- The presence of different salt forms only
- Different crystalline forms of the same chemical substance
- The formation of amorphous impurities during synthesis
- The conversion of a drug into a liquid dosage form
Correct Answer: Different crystalline forms of the same chemical substance
Q4. Which analytical technique is most useful for identifying crystalline polymorphs of a drug?
- High-performance liquid chromatography (HPLC)
- Ultraviolet-visible spectroscopy (UV-Vis)
- X-ray powder diffraction (XRD)
- Potentiometry
Correct Answer: X-ray powder diffraction (XRD)
Q5. A hydrate form of an API means:
- The drug is covalently bonded to a solvent molecule
- Water molecules are incorporated into the crystal lattice
- The drug is converted into an amorphous gel
- The drug is dispersed in oil to form an emulsion
Correct Answer: Water molecules are incorporated into the crystal lattice
Q6. Which micromeritics parameter directly influences flowability of powder during tablet manufacturing?
- pH value
- Angle of repose
- Partition coefficient
- Boiling point
Correct Answer: Angle of repose
Q7. A high Hausner ratio (>1.25) indicates:
- Excellent solubility
- Poor flow and high compressibility
- High chemical purity
- Low melting point
Correct Answer: Poor flow and high compressibility
Q8. Which semi-solid dosage form is an emulsion primarily used for skin application?
- Tablet
- Cream
- Elixir
- Suppository
Correct Answer: Cream
Q9. Which property of a drug crystal most directly affects its dissolution rate?
- Crystal habit and specific surface area
- Color of the crystal
- Odor threshold
- Boiling point of its solvent
Correct Answer: Crystal habit and specific surface area
Q10. Which morphological change typically increases a drug’s dissolution rate and bioavailability?
- Conversion from amorphous to crystalline form
- Increase in particle size
- Reduction in particle size (micronization)
- Formation of larger agglomerates
Correct Answer: Reduction in particle size (micronization)
Q11. Which dosage form classification is based on route of administration rather than physical state?
- Oral, topical, parenteral, inhalation
- Tablet, capsule, syrup, ointment
- Crystalline, amorphous, polymorphic
- Hydrate, solvate, co-crystal
Correct Answer: Oral, topical, parenteral, inhalation
Q12. Which excipient function is most related to morphology and powder behavior?
- Preservative action
- Lubrication and anti-adherent to improve flow
- Flavour enhancement
- pH buffering in solution
Correct Answer: Lubrication and anti-adherent to improve flow
Q13. Which coating type is used to protect an oral tablet from stomach acid and allow release in the intestine?
- Film coating
- Sugar coating
- Enteric coating
- Immediate-release coating
Correct Answer: Enteric coating
Q14. In suspensions, what morphological factor helps prevent sedimentation?
- Use of large, dense particles only
- Particle size reduction and viscosity modification
- Complete solubilization of the drug
- Removal of all surfactants
Correct Answer: Particle size reduction and viscosity modification
Q15. Which morphological classification term describes systems like liposomes and nanoparticles?
- Bulk solids
- Colloidal systems
- Gaseous dosage forms
- Enteric matrices
Correct Answer: Colloidal systems
Q16. Which of the following affects powder porosity and compaction behavior in tablet compression?
- Particle shape and size distribution
- Color of the powder
- Vapor pressure
- Optical rotation
Correct Answer: Particle shape and size distribution
Q17. Which inhalation dosage form is a dry solid particle that relies on patient inspiratory flow?
- Metered dose inhaler (MDI)
- Dry powder inhaler (DPI)
- Nebulized solution
- Transdermal patch
Correct Answer: Dry powder inhaler (DPI)
Q18. A change from crystalline to amorphous form usually results in:
- Decreased solubility and increased stability
- Increased melting point
- Increased solubility but often reduced physical stability
- No change in dissolution behavior
Correct Answer: Increased solubility but often reduced physical stability
Q19. Which test assesses tablet mechanical resistance related to morphological quality?
- Disintegration test
- Friability test
- pKa determination
- Viscosity measurement
Correct Answer: Friability test
Q20. Which morphological feature is most critical for dermal penetration from topical formulations?
- Tablet hardness
- Vehicle rheology and particle/vehicle interaction
- Boiling point of active
- Color of the cream
Correct Answer: Vehicle rheology and particle/vehicle interaction
Q21. Which term describes drugs that form a continuous phase of tiny droplets dispersed in another liquid phase?
- Emulsions
- Suspensions
- Tablets
- Gases
Correct Answer: Emulsions
Q22. Which characterization technique provides thermal transitions helping to identify polymorphs and hydrates?
- Infrared spectroscopy (FTIR)
- Differential scanning calorimetry (DSC)
- Optical rotation
- Atomic absorption spectroscopy
Correct Answer: Differential scanning calorimetry (DSC)
Q23. Which morphological classification best describes a suppository?
- Aqueous solution
- Semi-solid/solid designed for rectal or vaginal administration
- Inhalation aerosol
- Oral syrup
Correct Answer: Semi-solid/solid designed for rectal or vaginal administration
Q24. Which factor related to morphology can lead to batch-to-batch variability in dissolution?
- API polymorphic form and particle size distribution
- Brand logo printing
- Type of packaging color
- Storage room lighting
Correct Answer: API polymorphic form and particle size distribution
Q25. Which morphological property is measured by Carr’s index?
- Compressibility and flowability of powders
- pH of a solution
- Viscosity of a cream
- Surface tension of an emulsion
Correct Answer: Compressibility and flowability of powders
Q26. Transdermal patches are classified morphologically as:
- Colloidal suspensions
- Solid matrix or reservoir systems applied topically
- Oral immediate-release tablets
- Gaseous inhalants
Correct Answer: Solid matrix or reservoir systems applied topically
Q27. Which excipient type is used to stabilize emulsions by reducing interfacial tension?
- Surfactants
- Binders
- Fillers
- Disintegrants
Correct Answer: Surfactants
Q28. Which morphological test helps visualize particle shape and surface topography?
- Light or electron microscopy
- Titration
- Gas chromatography
- Polarimetry
Correct Answer: Light or electron microscopy
Q29. Modified-release tablets that rely on matrix morphology to control drug release are called:
- Immediate-release tablets
- Matrix sustained-release tablets
- Effervescent tablets
- Chewable tablets
Correct Answer: Matrix sustained-release tablets
Q30. Which morphological characteristic is most relevant when designing a dry powder inhaler formulation for deep lung delivery?
- Particle aerodynamic diameter and fine particle fraction
- Tablet disintegration time
- Melting point of the API
- Color of the capsule shell
Correct Answer: Particle aerodynamic diameter and fine particle fraction
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.
Mail- Sachin@pharmacyfreak.com