General Rules of Drug Collection (Pharmacognosy)

1. Collection at the Right Stage of Growth

• Leaves & herbs — collected just before or during flowering (active constituents peak at this stage)
• Flowers — collected when fully open or just before full bloom
• Fruits — collected when fully ripe (alkaloids, glycosides at maximum)
• Seeds — collected after the fruit is fully ripe and dried
• Bark — collected in spring when the sap is rising and the bark separates easily from the wood
• Roots & rhizomes — collected in autumn (after aerial parts die down) or early spring before growth resumes, when carbohydrate and active constituent stores are highest

2. Collection at the Right Time of Day

• Many drugs are best collected in the morning after the dew has dried to avoid fermentation and microbial contamination.
• For volatile oil-containing plants (e.g., peppermint), collection is done early morning before the heat volatilizes the oils.

3. Collection Under Appropriate Climatic Conditions

• Collection should be done in dry weather to prevent microbial growth and spoilage during drying.
• Avoid collecting after rain or when plants are wet.

4. Correct Identification of Plant/Source

• The drug must be collected from the correct botanical species to ensure authenticity and avoid adulteration.
• Skilled collectors or trained personnel should verify identity using morphological, organoleptic, and chemical characteristics.

5. Proper Method of Collection

• Methods should not damage the drug material — bruising accelerates fermentation and degrades active principles.
• Only the appropriate part (leaf, root, bark, etc.) should be collected; extraneous matter should be excluded.
• Tools used should be clean and sharp to reduce damage and contamination.

6. Avoidance of Contamination

• Drug materials should not be mixed with foreign matter, soil, insects, or other plant species.
• Containers used for collection (baskets, sacks) should be clean and dry.
• Avoid collection near roadsides, industrial areas, or heavily fertilized/pesticide-treated land to minimize chemical contamination.

7. Sustainable and Ethical Collection

• Wild plants should not be over-harvested to preserve biodiversity.
• Only mature specimens should be collected, leaving younger plants to replenish the population.
• Collection should comply with local regulations regarding protected species.

8. Post-Collection Handling

• Collected material should be processed promptly (sorted, cleaned, dried) to prevent deterioration.
• Proper drying, storage, and packaging immediately follows collection to preserve active constituents.