Grinding and Storage of Medicinal Plants

Study Notes

Grinding dried plant material is necessary before storage to achieve a suitable and uniform particle size.
Grinding machines include: hammer mills, knife mills, tooth mills, blenders, and mortars and pestles.
Following grinding, sifting ensures proper particle size via sieving or blast sifting.
Sieving involves passing material through a sieve with a specific mesh size.
Blast sifting uses compressed air to separate particles by size and weight.

Storage and preservation of plant crude drugs must consider physical and chemical properties for maintaining quality.
Factors impacting storage include moisture, temperature, radiation, form/shape of the drug, atmospheric oxygen, fungi/mold/insect pests, shelf-life and packaging.
Moisture content affects drug quality, with the ideal range being 10-12% for most herbs and 15% for roots or sugar-containing herbs.
Desiccants like quicklime, silica gel, or roasted rice can be used to control moisture.
The optimum temperature for storage is 2-8°C, but some herbs can be stored at room temperature (25°C).
Direct sunlight can destroy active constituents, so storage should be in a dark place.
The form and shape of the drug influence storage.
Atmospheric oxygen can damage certain drugs, necessitating storage in tightly sealed containers or using inert gases like nitrogen.
Fungi, molds, and insects infest crude drugs during storage, requiring pest control measures like sun-drying, heat-drying, fumigation, or sterilization.
Herbs should be distributed annually to avoid excessive storage, which impacts quality.
Packaging should be in well-closed, water-proof, fire-proof, and rodent-proof containers, using dust-free and water-proof materials.
Precious items are stored with desiccants in sealed tin boxes.

Medicinal plants can be used whole, in parts, or as extracts.
Plant extracts are derived through solid-liquid extraction, separating elements from the plant material using a solvent.
Types of extracts: dry extracts (all solvent removed, solid), soft extracts (semi-solid, partial solvent removal), fluid extracts (concentrated liquid extracts), and tinctures (ethanol extraction without concentration).

Adulteration is intentional or unintentional substitution of original crude drugs with inferior or similar-looking substances.
Unintentional adulteration can occur due to confusion in plant names, lack of knowledge about the authentic plant, non-availability of the authentic plant, similarity in morphology or aroma, and careless collection.
Intentional adulteration tactics include:
- Adulteration with manufactured substances: materials resembling the original drug but lack therapeutic property.
- Substitution with inferior commercial varieties: similar morphology but reduced quality or activity.
- Substitution with exhausted drugs: original plant materials after extraction, potentially altering appearance artificially with additives.
- Substitution with superficially similar inferior natural substances: morphologically resembling but having no therapeutic value.

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