Plant Extraction Introduction

Plant Extraction Introduction

downstream processing

Around the world 35k to 70k plants are used by humans for medicinal and therapeutic purposes.

As we have gotten more and more used to homeopathic and allopathic drugs, we have forgotten the importance the knowledge of traditional medicine. Although, fortunately, medicine such as the Ayurveda and the Chinese medicine, have started gaining popularity across the globe.

This is not due to some campaigns but because now, finally, people are starting to realize the cost-effectiveness and reliability of traditional medicine is more, when compared to the popular medicine.

Plant extraction is the process by which the biologically active parts of a plant are harnessed and then are used for therapeutic and medicinal purposes. This is done by people who have both theoretical and practical knowledge of plants, along with solvents.

Galenicals – Named after the Greek physician of the second century, Galen. The term is a generic name for preparations such as infusions, decoctions, powdered extracts, fluid extracts, semisolid extracts and tinctures.

One of the fields in which these plants extracts are used the most, is the cosmetic field. Cosmetic products are the products which are used to change appearance, odor or other characteristics of a body part, such as the lips, face, eyes, ears, skin, genital areas and others.

A plant extract, is a biologically active tissue of a plant, that is preserved using a solvent and must have the following qualities, to be called one:

  • Should serve the physical and chemical needs
  • Regulation in terms of legal uses, certification, claims and more
  • Activity, adulteration, toxicity, stability, and such particular standards of quality should be followed

Plant Extraction

Raw materials

Before plant extraction, a survey should be done to determine the regions in which the required plant is in abundance, and the regions in which it’s not. Along with this, the soil, weather, rules and regulations of the region also need to be analyzed. Also, the middlemen and labor costs should also be taken into account.

Last but not the least, it should be determined if the harnessing of the plant extract affects the environment. In case it does, actions should be taken to reduce this impact.


The quality of the plant extract relies on multiple factors, such as the equipment and solvents used. The quality is very important as a compromise on the quality, can lead to severe results which may prove fatal for the consumer.

The dry form of a plant extract is preferred over the liquid form as the former doesn’t contain any unnecessary substances, such as metabolites. The preparation of these extracts often consists of various processes, freezing, decoating, destemming, cooking and more. These processes take place before the extraction.

Once extracted, the plant extracts have to go through multiple tests such as the disc diffusion test, antimicrobial susceptibility test and others. Other processes such as identifying bacterial strains, preparation of impregnated discs, and sterility proofing also take place.

Extraction of plants


Any solvent that is used in the plant extraction process, should comply with the government’s regulatory standards. The solvent should be chosen wisely as it affects the yield of the extraction. Some of the most used solvents are acetic acid, methanol, Acetone, water and ethanol.

The effects that these solvents have on the nature and the environment, should also be taken into account. It is only fair to have full disclosure to your customers about the solvents that you’ve used during the extraction

Choosing a solvent

The dipole movement of a solvent, is the best way of selecting a solvent. The dipole movement of a substance is a vector quantity (measured in either coulomb or debye) and is a measure of the separation of positive and negative charges inside the substance.

This dipole movement is the basis for the classification of solvents.

  • Low polar and apolar solvents – These are the solvents which have a dipole movement between 0 to 1.5. These have a tendency to dissolve or combine in fats, which is why they are called lipophilic (fat affinity). Examples – cyclohexane, chloroform, phenol, ethylic ether, dimethoxymethane and others.
  • Polar aprotic solvent – These are attracted to water and are thus called “hydrophilic”.
    • Polar protic solvents and polar aprotic solvents share ion dissolving abilities but leave out a hydrogen ion (that’s acidic).
    • These solvents generally have high dielectric constants and show high polarity.


As we have mentioned before in the article, natural treatments are gaining preference among patients and consumers because of their cost-effectiveness, less or no harm to the environment and reduced or no side effects. This is simply the reason that we have started moving back to our roots (literally) since the past few decades. We hope that the movement will gain more popularity in the future and we’ll learn the value of going natural.

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