Evaluation of commercial crude drugs intended for medicinal use is a core topic in pharmacognosy and quality control for B.Pharm students. This introduction covers sampling, organoleptic and microscopic identification, physico‑chemical parameters (ash values, loss on drying, extractive values), chromatographic techniques (TLC/HPTLC, HPLC, GC), and modern authentication tools (DNA barcoding, heavy metal and microbial limit tests). Emphasis is on pharmacopoeial standards, adulteration detection, stability, and regulatory guidelines such as WHO and national pharmacopoeias. Understanding these concepts ensures safe, effective herbal medicines and reliable analytical data for routine quality control. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which sampling approach is essential to obtain a representative sample of a large commercial crude drug batch?
- Taking a single portion from the top of the batch
- Representative sampling by collecting multiple, well-distributed increments
- Sampling only the bottom layer
- Sampling only visibly clean portions
Correct Answer: Representative sampling by collecting multiple, well-distributed increments
Q2. Which organoleptic parameters are routinely evaluated during primary assessment of crude drugs?
- Taste, color, odour, and texture
- pH and viscosity only
- Melting point and refractive index
- Chromatographic profile only
Correct Answer: Taste, color, odour, and texture
Q3. How is foreign matter in crude drug samples usually quantified according to pharmacopoeial practice?
- By visual estimate only
- By weighing the separated foreign matter and calculating percentage
- By heating the sample to constant weight
- By TLC analysis
Correct Answer: By weighing the separated foreign matter and calculating percentage
Q4. Which reagent is commonly used in microscopy to detect lignified tissues in powdered plant drugs?
- Iodine solution
- Phloroglucinol-HCl
- Sudan III
- Mayer’s reagent
Correct Answer: Phloroglucinol-HCl
Q5. What is the characteristic colour change when starch is treated with iodine solution in powder microscopy?
- Red
- Blue‑black
- Green
- No change
Correct Answer: Blue‑black
Q6. Which ash value is most useful to detect siliceous contamination such as sand in a crude drug?
- Total ash
- Acid‑insoluble ash
- Water‑soluble ash
- Sulphated ash
Correct Answer: Acid‑insoluble ash
Q7. Which analytical technique gives a direct and specific measurement of water content in herbal drugs?
- Loss on drying at 105°C
- Karl Fischer titration
- Gravimetric ash determination
- Thin layer chromatography
Correct Answer: Karl Fischer titration
Q8. What do alcohol and water extractive values primarily estimate in crude drugs?
- Total ash content
- Amount of constituents soluble in the respective solvents
- Microbial contamination
- Heavy metal content
Correct Answer: Amount of constituents soluble in the respective solvents
Q9. What is a key advantage of HPTLC over classical TLC for fingerprinting herbal extracts?
- Lower resolution
- Better separation, reproducibility and quantitative capability
- It requires no sample preparation
- It replaces the need for pharmacopoeial tests
Correct Answer: Better separation, reproducibility and quantitative capability
Q10. Which stationary phase is most commonly used in TLC for phytochemical screening?
- Silica gel
- Polystyrene resin
- Glass beads
- Cellulose acetate only
Correct Answer: Silica gel
Q11. How is Rf value in thin layer chromatography defined?
- Distance travelled by the solvent front divided by distance travelled by the solute
- Distance travelled by the solute divided by distance travelled by the solvent front
- Height of the chromatogram peak
- Ratio of peak area to solvent volume
Correct Answer: Distance travelled by the solute divided by distance travelled by the solvent front
Q12. Which apparatus is standard for estimating volatile oil content from plant materials?
- Rotary evaporator
- Clevenger apparatus
- Kjeldahl apparatus
- HPLC system
Correct Answer: Clevenger apparatus
Q13. The foaming index is a pharmacopoeial test primarily used to detect which class of phytoconstituents?
- Tannins
- Saponins
- Alkaloids
- Steroids
Correct Answer: Saponins
Q14. What does the swelling index of a powdered crude drug indicate?
- Concentration of volatile oils
- Amount of mucilage and swelling capacity of polysaccharides
- Heavy metal contamination
- Degree of lignification
Correct Answer: Amount of mucilage and swelling capacity of polysaccharides
Q15. Which analytical technique is commonly preferred for quantitative determination of heavy metals in crude drug samples?
- Thin layer chromatography
- Atomic absorption spectroscopy (AAS) or ICP
- Paper chromatography
- Colorimetry using anisaldehyde
Correct Answer: Atomic absorption spectroscopy (AAS) or ICP
Q16. Microbial limit tests for herbal drugs typically include which assessments?
- Total aerobic microbial count and absence of specified pathogens like Salmonella and E. coli
- Only pH measurement
- Only fungal staining
- Only Gram staining
Correct Answer: Total aerobic microbial count and absence of specified pathogens like Salmonella and E. coli
Q17. Which method is commonly used for sensitive quantification of aflatoxins in botanicals?
- HPLC with appropriate detection (e.g., fluorescence)
- Simple visual inspection
- Gravimetric ash analysis
- Paper chromatography
Correct Answer: HPLC with appropriate detection (e.g., fluorescence)
Q18. How does DNA barcoding aid evaluation of commercial crude drugs?
- By measuring ash values
- By authenticating species identity and detecting adulteration
- By estimating volatile oil content
- By replacing all chemical tests
Correct Answer: By authenticating species identity and detecting adulteration
Q19. Which elements are typically included in a pharmacopoeial monograph for a crude drug?
- Identification tests, purity limits, assay methods, and storage conditions
- Only chromatographic fingerprints
- Only the botanical name
- Clinical trial data
Correct Answer: Identification tests, purity limits, assay methods, and storage conditions
Q20. Which derivatization reagent is commonly used to visualize many classes of phytoconstituents on TLC plates?
- Ninhydrin solution
- Anisaldehyde‑sulfuric acid
- Molisch reagent
- Benedict’s reagent
Correct Answer: Anisaldehyde‑sulfuric acid
Q21. Which solvent is typically used for extracting highly polar constituents like glycosides and sugars for extractive value determination?
- Petroleum ether
- Water
- Chloroform
- Hexane
Correct Answer: Water
Q22. Which simple chemical test indicates the presence of hydrolyzable and condensed tannins in plant extracts?
- Ferric chloride producing blue‑black or green coloration
- Dragendorff’s reagent producing orange precipitate
- Bornträger’s test producing pink colour
- Biuret test giving violet colour
Correct Answer: Ferric chloride producing blue‑black or green coloration
Q23. Which chromatographic technique is most suitable for separation and analysis of volatile constituents from essential oils?
- HPTLC
- Gas chromatography (GC)
- TLC with water mobile phase
- Paper chromatography
Correct Answer: Gas chromatography (GC)
Q24. For accurate quantification of a specific marker compound in plant extracts, which technique is most widely employed?
- Thin layer chromatography without densitometry
- High performance liquid chromatography (HPLC)
- Simple color reaction
- Loss on drying
Correct Answer: High performance liquid chromatography (HPLC)
Q25. What is the primary objective of standardization of commercial crude drugs?
- To increase the moisture content
- To ensure consistent quality, safety and therapeutic efficacy
- To eliminate all natural variability
- To change botanical identity
Correct Answer: To ensure consistent quality, safety and therapeutic efficacy
Q26. Which parameter best reflects the amount of inorganic non‑combustible residue present in a crude drug?
- Extractive value
- Ash values (total ash and its types)
- Foaming index
- Swelling index
Correct Answer: Ash values (total ash and its types)
Q27. Which international organization provides guidance and quality control recommendations for herbal medicines and crude drugs?
- FDA only
- World Health Organization (WHO)
- ISO only
- WTO
Correct Answer: World Health Organization (WHO)
Q28. What does a high water‑soluble extractive value indicate about a crude drug?
- High content of non‑polar constituents
- High amount of polar, water‑soluble constituents such as sugars and glycosides
- High inorganic ash
- Low extractability in all solvents
Correct Answer: High amount of polar, water‑soluble constituents such as sugars and glycosides
Q29. Which approach most effectively detects visual and morphological adulteration in bulk plant drugs at marketplace level?
- Organoleptic and macroscopic/microscopic examination
- HPLC quantification only
- Determination of ash values only
- Microbial limit tests only
Correct Answer: Organoleptic and macroscopic/microscopic examination
Q30. Which of the following is NOT typically part of pharmacognostical evaluation of a crude drug?
- Macroscopic and microscopic description
- Phytochemical screening and TLC fingerprint
- Clinical efficacy trials in patients
- Physico‑chemical parameters like ash and extractive values
Correct Answer: Clinical efficacy trials in patients
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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