3. CULTIVATION, COLLECTION, PROCESSING AND STORAGE OF CRUDE DRUGS

Introduction

Crude drugs are natural substances obtained from plants, animals or minerals. Their quality depends on proper cultivation, collection, processing and storage. Good practices at every stage ensure that the active constituents remain stable and effective. Poor handling can reduce potency or lead to contamination and spoilage. This chapter provides a simple overview of the main steps involved.

Cultivation of Medicinal Plants

Cultivation means growing medicinal plants under controlled and favourable conditions. The aim is to produce uniform, good-quality crude drugs with high yield and correct chemical constituents.

Factors Affecting Cultivation

Climate: Temperature, rainfall, humidity and sunlight influence plant growth and active chemical content.
Soil: pH, nutrients and texture determine root development and yield. Loamy and well-drained soil suits most medicinal plants.
Altitude: Certain plants grow better at specific heights due to air pressure and temperature.
Water: Proper irrigation is needed. Excess water causes fungal growth, while low water reduces yield.
Fertilizers: Organic manure is preferred to avoid chemical contamination.

Methods of Propagation

Propagation is how new plants are produced.

Sexual propagation: Seeds are used to produce new plants. It is simple and suitable for most species.
Asexual propagation: Methods like cutting, layering, grafting and division give genetically identical plants.

Pest and Disease Control

Healthy soil and crop rotation help prevent pests.
Biological control is preferred over chemical pesticides.
Proper spacing and weeding reduce fungal growth.

Good Agricultural Practices (GAP)

GAP guidelines ensure the quality and safety of herbal raw material. They include proper land selection, safe water supply, clean harvesting tools, proper drying and careful storage.

Collection of Crude Drugs

Correct collection ensures maximum active constituents. The maturity stage of the plant part is important.

Best Collection Time

Roots and rhizomes: Collected at the end of the growing season when stored constituents are highest.
Bark: Collected during spring when it separates easily.
Leaves: Collected before flowering when volatile oil content is higher.
Flowers: Collected just before or at full bloom.
Fruits and seeds: Collected when fully ripe.

Collection Precautions

Use clean tools and avoid damaging the plant unnecessarily.
Remove soil, insects and unwanted plant parts immediately.
Collect in dry weather to prevent fermentation.

Processing of Crude Drugs

Processing involves preparation steps that help preserve the drug in usable form.

Washing

Drugs collected from the ground (roots, rhizomes) are washed to remove soil and dirt. Washing should be gentle to avoid loss of active compounds.

Cutting and Sizing

Large plant parts are cut into smaller pieces to promote uniform drying and easy packing.

Drying

Drying prevents spoilage by reducing moisture content.

Sun drying: Used for drugs not affected by heat, such as roots and bark.
Shade drying: Used for leaves and flowers to protect volatile oils.
Artificial drying: Mechanical dryers maintain controlled temperature and humidity.

Garbling

Garbling means removing foreign matter such as soil, stones, insects and other plant parts. It improves appearance, purity and quality.

Packing

Proper packing protects crude drugs during transport. Clean, dry, airtight containers are preferred. Fragile items like flowers need extra cushioning.

Storage of Crude Drugs

Storage plays a major role in maintaining the stability and potency of crude drugs. Poor storage can lead to moisture absorption, insect attack, mould growth and loss of volatile or active constituents.

General Storage Conditions

Store in cool, dry and well-ventilated places.
Use airtight and moisture-resistant containers.
Protect from direct sunlight to avoid chemical degradation.
Keep away from pests and rodents.
Regularly check for moisture, fungal growth or signs of spoilage.