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How to Evaluate the Extractive Values of Crude Drug?

How to Evaluate the Extractive Values: The extractive values of crude drugs are those constituents which can be extracted from the drug by using solvent. These are generally alkaloids, glycosides, tannins etc. The determination of these values is important from the pharmacognostical and pharmacological point of view.

Extractive values of crude drug are the amount of active ingredient in a given quantity of plant material. The higher the extractive value (How to determine the Ash Value), the more potent the plant material.

Extractive values are determined by the percentage of volatile oil or other desirable principles extracted from a botanical material. The results are then corrected to standardize the extractive value to 100% pure raw plant material. This process is used to determine the potency of essential oils, oleoresins, absolutes and concretes.

Extractives values
Extractives values

What are Crude Drugs?

Crude drug refers to the unrefined or minimally processed plant, animal or mineral sources used for the production of traditional medicines. Crude drugs are usually in the form of powders, pastes, tinctures, extracts and crude saponins. The use of crude drugs has been declining globally due to advances in medical science and technology which have resulted in the development of more sophisticated and effective medicines. However, there is still a large demand for crude drugs in developing countries where access to modern medicine is limited.

Different Extraction Method

What is plant extraction? Plant extraction is a process where compounds are taken from plants in order to be used for various purposes. This can be done through a number of methods, such as solvent extraction, supercritical fluid extraction, and pressurized liquid extraction. Plants contain a wide variety of compounds that can be used for medicinal purposes, cosmetics, food flavoring, and more. By extracting these compounds from plants, they can be put to good use instead of being wasted.

There are many ways to extract the desired plant parts from an herbal plant. The most common method is to use a solvent such as alcohol or water. Other solvents that can be used include vinegar, glycerin, and propylene glycol. The plant material is placed in the solvent and allowed to soak for a period of time. The longer the soaking time, the more potent the extraction will be. After soaking, the plant material is strained out and the extract is collected.

Cold Extraction

Cold extraction is the process of using solvents to remove essential oils from plant material. This type of extraction is typically used for harder-to-find or delicate ingredients, like jasmine and ylang-ylang flowers. Cold extraction is a very precise and labor-intensive process, which is why these oils tend to be more expensive than others on the market.

Hot Extraction

Hot extraction is a process in which an solvent is used to extract oils, fats, and other lipid soluble materials from a solid substrate. The hot extraction process is often used to extract these materials from plant sources, but can also be used on animal products such as lard or tallow. Hot extraction usually involves the use of a Soxhlet apparatus, which allows for the efficient extraction of the desired materials.


Successive plant extraction and concentration steps are used to produce a natural product with the desired chemical composition. Aqueous-based and organic-based extraction methods are used to isolate the desired compound from plant material. The choice of solvent and method of extraction is based on the solubility of the compound in different solvents and the ease of removal of the solvent.

How to Determine the Extractive Values?

The extractive values of crude drugs are determined by taking the weight of the drug and dividing it by the volume of solvent used. The results are then multiplied by 100 to give the percentage of extractive value.

Water Soluble Extractive Values

The water extractive values of a crude drug are the percentage of water-soluble material present in the drug. This information is important for Quality Control purposes, as it allows for an estimation of the potency of the active ingredients in the drug. The water extractive values also give an indication of the stability of the crude drug during storage.

It plays an important role in the evaluation of crude drugs. The less extractive value is an indication of exhausted material or incorrect processing during formulation or storage. If the water is used as a solvent it is known as water-soluble extractive value.

Water soluble extractive = value (%w/w)

Alcohol soluble extractive value

Alcohol soluble extractive value is the amount of alcohol required to completely extract a given volume of an herb or other material. This is typically expressed as a percentage of the total volume of the material being extracted. For example, if it takes 100 mL of alcohol to completely extract the active ingredients from 100 g of an herb, then that herb would have an alcohol soluble extractive value of 100%.

Alcohol soluble extractive = value (%w/w)

Importance of Extractive Values

Extractive values are very important in the quality control of crude drugs. They provide an estimate of the overall chemical composition of the drug and help to identify potential impurities. Extractive values can also be used to determine the suitability of a crude drug for use in traditional medicine.

Crude drugs are the naturally occurring substances that are used for the treatment of various diseases. They have been used in traditional medicines for centuries and their extracts have a wide range of therapeutic properties. The extractive values of crude drugs play an important role in determining their efficacy and safety. Extractive values help to identify the active constituents of a crude drug and also determine its dosage form, potency, and purity.

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1 thought on “How to Evaluate the Extractive Values of Crude Drug?”

  1. Pingback: Soxhlet Extraction Process- Plant Extraction Method

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