Drug Extraction

Cyclodextrins (CDs) can form host-guest supramolecular inclusion complexes with drug molecules of appropriate size. The advantages of these noncovalent complexes are increased aqueous solubility and stability of unmanipulated drugs ^[1]. Consequently, CDs are increasingly being used to extract active ingredients from natural sources.

Chinese materia medica (CMM), often referred to simply as traditional Chinese drugs, is important to modern healthcare, and its extraction methods are usually heat or reflux with organic solvents. As the demand for cheaper, safer, and more environmentally friendly alternatives to organic solvents has increased in recent years, CD-based extraction of CMM has aroused great interest as an emerging "green" technology.

Advantages of CD-assisted Extraction

In the extraction of the active components of CMM, CD-assisted extraction can improve the solubility and stability of active components of CMM, as described below ^[2].

• Improve solubility: The insoluble components of CMM can be combined with CD molecules to form water-soluble CD inclusion complexes. They can coexist with non-inclusion CD complexes in aqueous solutions, jointly improving the solubility of the desired components.
• Improve stability: Unstable molecular portions of CMM components that are easily oxidized, hydrolyzed, or volatilized can be included in CD cavities to protect them from environmental impacts. This allows the active ingredients in the CMM to always have good stability during the extraction process, and their activity may not be impaired.

Extraction Methods

There are many CD-assisted extraction methods, including solvent-assisted extraction, microwave-assisted extraction, and ultrasonic-assisted extraction ^[2].

• Solvent-assisted extraction

Solvent-assisted extraction can be divided into water and organic solvent extraction according to the active components in CMM. The former has the disadvantage of low extraction efficiency and is only suitable for water-soluble substances, while the latter has higher costs and solvent safety issues. Solvent-assisted extraction based on CD is not only suitable for fat-soluble components in CMM, but also can avoid the above problems. It has the advantages of being low-cost, easy to operate, highly efficient, and environmentally friendly.

• Microwave-assisted extraction

Microwave-assisted extraction can selectively separate target components directly from the sample matrix by heating the solvent with microwave energy. Although its extraction efficiency is high, the temperature rises quickly and evenly, and the extraction time is shortened, this method is not suitable for heat-sensitive substances. Using CDs and CMM components to form inclusion complexes can enhance the stability of drug ingredients and compensate for the shortcomings of conventional microwave-assisted extraction.

• Ultrasonic-assisted extraction

Ultrasound-assisted extraction uses ultrasound energy and solvents to realize CMM extraction. Ultrasound has a cavitation effect, thermal effect, mechanical effect, and chemical effect, which can accelerate the dissolution of components in CMM. Ultrasonic-assisted extraction based on CDs not only maintains the properties of the active ingredients in CMM, but also is efficient and time-saving, and expands the application scope of ultrasonic-assisted extraction technology.

Alfa Chemistry is dedicated to the manufacture of CDs. We offer high-quality native CDs, CD derivatives, and CD inclusion complexes. We have strong supply capabilities and can provide products at the kilogram level. Please feel free to contact us and we will serve you wholeheartedly.

It should be noted that our our products and services are for research use only, not for clinical use.