Methods of preliminary preparation of herbal materials, traditional medicinal materials in Vietnam

Methods of preliminary preparation of herbal materials, traditional medicinal materials in Vietnam

Preliminary preparation of medicinal materials is the process of performing one or more of the following operations: removing impurities, soaking, washing, fermenting, cutting into segments, slicing, drying, and baking to create preliminarily processed medicinal materials.

There are 07 methods of preliminary preparation of herbal materials, prepared traditional medicinal materials in Vietnam as follows:

(1) Impurity Removal Method

* Purpose:

- Eliminating non-usable parts that do not meet the drug standards;

- Removing parts that cause undesirable effects;

- Removing impurities mixed in during drying and toxic impurities;

- Creating uniformity in terms of size.

* Processing Technique: Eliminate parts not used as drugs (secondary roots, root tips, root cores, hairs, cork layers...).

(2) Washing Method

* Purpose:

- Cleaning the medicinal materials;

- Softening the medicinal materials;

- Deodorizing certain medicinal materials (using the decoction of some medicinal materials with essential oils);

- Reducing undesirable effects.

* Processing Technique: Wash with clean water to remove mechanical impurities (soil, sand, gravel...). Wash 1 - 3 times depending on the type of medicinal material. Drain, dry, or bake until dry.

(3) Soaking Method

* Purpose:

- Softening the medicinal materials to facilitate slicing, cutting, and processing;

- Removing salts adhered to the medicinal materials, eliminating impurities;

- Reducing toxicity, removing itchiness, reducing undesirable effects;

- Enhancing drug conduciveness.

* Processing Technique: Clean the medicinal materials, then soak them in water (usually let the water soak into about 30% of the medicinal materials). The soaking time depends on the nature, size, purpose of use, and season temperature. During soaking, frequently stir and change the water multiple times.

(4) Fermentation Method

* Purpose:

- Softening medicinal materials to facilitate slicing, cutting;

- Fermenting medicinal materials;

- Fragrancing medicinal materials;

- Shaping immediately after harvesting;

- Allowing auxiliary substances to penetrate the medicinal materials.

* Processing Technique: Clean the medicinal materials, place them in a sealed device to ferment. During fermentation, stir or spray water, auxiliary substances until the desired level is reached. Take out, drain water.

(5) Slicing, Segmenting Method

* Purpose: Dividing medicinal materials into appropriate sizes.

* Processing Technique: Wash, soak, ferment or soften medicinal materials before slicing or segmenting.

Depending on the characteristics of the medicinal materials and specific requirements, proceed to slice or segment the medicinal materials with suitable equipment to the appropriate size.

(6) Drying Method

* Purpose: Drying medicinal materials, preserving medicinal materials.

* Processing Technique:

- Indirect drying (not directly under the sun): applies to medicinal materials containing essential oils.

After slicing or segmenting, spread the medicinal materials evenly on trays, proceed to dry in a shaded, well-ventilated area until the desired moisture content is achieved.

- Direct drying under the sun: applies to all medicinal materials, except those containing essential oils.

After slicing or segmenting, spread the medicinal materials evenly on trays, proceed to dry in the sun until the desired moisture content is achieved.

(7) Baking Method

* Purpose: Drying medicinal materials, preserving medicinal materials.

* Processing Technique: Place medicinal materials on baking trays, set temperature and time suitable for each type of medicinal material. Bake until the desired moisture content is achieved.

More details can be found in Circular 14/2024/TT-BYT which comes into force in Vietnam from October 20, 2024.

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