Preparation process of Calendula officinalis extract.

1. Introduction

Calendula, scientifically known as Calendula officinalis, has been highly valued for its various properties. The extract of Calendula is widely utilized in cosmetics and medicine industries. In cosmetics, it is often used for its skin - soothing, anti - inflammatory, and antioxidant properties. In medicine, it can be applied in treating skin diseases, promoting wound healing, etc. Due to its diverse applications, the preparation process of Calendula Extract is of great significance.

2. Raw Material Selection

The quality of the raw material is the foundation of obtaining a high - quality Calendula Extract.

2.1. Plant Source

Calendula officinalis plants should be carefully selected. Organically grown plants are preferred as they are less likely to be contaminated with pesticides and other harmful substances. The plants should be in good health, free from diseases and pests. They are usually harvested at the appropriate time. For example, the flowers are often harvested when they are fully bloomed, which is when they contain the highest concentration of active ingredients.

2.2. Storage and Preservation

After harvesting, proper storage and preservation of the raw materials are crucial. The Calendula flowers should be stored in a cool, dry place to prevent mold growth and degradation of the active components. If not processed immediately, they can be dried using appropriate methods, such as air - drying or low - temperature drying, to maintain their quality.

3. Extraction Methods

There are several common extraction methods for obtaining Calendula Extract.

3.1. Solvent Extraction

• Solvent selection: Ethanol is one of the most commonly used solvents for Calendula extraction. It has good solubility for the active ingredients in Calendula, such as flavonoids, triterpenoids, and carotenoids. Ethanol is also relatively safe and easy to handle. However, other solvents like water, ethyl acetate, or mixtures of solvents can also be used depending on the specific requirements of the extraction.
• Extraction process: The dried Calendula flowers are first ground into a fine powder. Then, a certain ratio of solvent (e.g., ethanol - water mixture in a certain proportion) is added to the powdered flowers. The mixture is stirred thoroughly and allowed to stand for a period of time. This standing time, known as the extraction time, can range from several hours to days. For example, it may be left for 24 - 48 hours at room temperature. During this time, the solvent penetrates the plant material and dissolves the active ingredients.
• Filtration: After the extraction time, the mixture is filtered to separate the liquid extract from the solid residue. This can be done using filter paper, a Buchner funnel, or other filtration devices. The filtrate contains the dissolved Calendula extract.

3.2. Maceration

• Maceration is a traditional extraction method. In this method, the whole or coarsely chopped Calendula flowers are placed in a container with a solvent (such as ethanol or oil). The container is sealed and left to stand for an extended period, usually weeks to months. For example, in the case of an oil - based maceration, the Calendula flowers may be left in olive oil for 4 - 6 weeks at room temperature. During this time, the active ingredients gradually diffuse into the solvent.
• After the maceration period, the liquid is separated from the plant material by filtration or decantation. The resulting liquid is the Calendula macerate, which contains the extract.

3.3. Distillation

• Distillation is often used in combination with other extraction methods to obtain a more concentrated Calendula extract. After the initial extraction using solvent extraction or maceration, the resulting extract can be subjected to distillation. The principle of distillation is based on the different boiling points of the components in the extract.
• For example, in the case of an ethanol - based extract, when heated, the ethanol will evaporate first due to its lower boiling point. The evaporated ethanol can be condensed and collected, leaving behind a more concentrated Calendula extract. This helps to remove excess solvent and increase the concentration of the active ingredients in the extract.

4. Quality Control

Quality control is essential throughout the preparation process of Calendula extract to ensure the purity and effectiveness of the final product.

4.1. Identification of Active Ingredients

• Various analytical techniques are used to identify and quantify the active ingredients in the Calendula extract. High - performance liquid chromatography (HPLC) is a commonly used method. It can separate and detect different compounds in the extract, such as flavonoids and triterpenoids. By comparing the chromatogram of the extract with standard samples, the presence and quantity of these active ingredients can be determined.
• Another method is spectrophotometry, which can measure the absorbance of the extract at specific wavelengths corresponding to the active ingredients. This helps in assessing the concentration of certain compounds in the extract.

4.2. Purity and Contamination Checks

• To ensure the purity of the Calendula extract, tests for contaminants such as heavy metals, pesticides, and microbial contaminants are necessary. Atomic absorption spectroscopy can be used to detect heavy metals like lead, mercury, and cadmium. If the levels of these heavy metals exceed the acceptable limits, the extract may be considered unfit for use.
• For pesticide residues, gas chromatography - mass spectrometry (GC - MS) is a powerful tool. It can identify and quantify different pesticides in the extract. Microbial contamination can be detected by standard microbiological tests, such as total plate count, yeast and mold count, and tests for specific pathogens.

4.3. Stability Testing

• Calendula extract should be stable over a certain period of time to ensure its effectiveness. Accelerated stability testing can be carried out by subjecting the extract to conditions such as high temperature, high humidity, and light exposure for a short period. This mimics the long - term storage conditions and helps to predict the stability of the extract. If significant degradation of the active ingredients occurs during the accelerated stability test, appropriate measures such as adjusting the formulation or storage conditions need to be considered.
• Long - term stability testing is also important, where the extract is stored under normal storage conditions for an extended period (e.g., months to years) and periodically tested for the content and activity of the active ingredients.

5. Conclusion

The preparation process of Calendula extract involves multiple steps from raw material selection to extraction methods and quality control. Each step is crucial in obtaining a high - quality extract with desired purity and effectiveness. With the increasing demand for Calendula extract in cosmetics and medicine, continuous research and improvement in the preparation process are necessary to ensure its safety and efficacy in various applications.

FAQ:

1. What are the main raw materials for preparing Calendula extract?

The main raw material for preparing Calendula extract is Calendula officinalis. This plant is rich in various bioactive compounds, which are the basis for the extract to have different functions.

2. Why is ethanol often used as a solvent in the extraction process?

Ethanol is often used as a solvent in the extraction of Calendula extract because it can effectively dissolve many of the active components in Calendula officinalis. Ethanol has appropriate polarity, which can extract a wide range of compounds such as flavonoids and terpenoids from the plant material. Also, ethanol is relatively safe and can be easily removed during the subsequent distillation process.

3. What are the key points of the maceration process?

The maceration process involves soaking the Calendula officinalis in the solvent (such as ethanol) for a certain period. Key points include maintaining an appropriate temperature, usually room temperature or a slightly elevated temperature. The time of maceration is also crucial, which is typically several hours to days, depending on the desired extraction efficiency. Also, the ratio of raw materials to solvent should be well - controlled to ensure sufficient extraction.

4. How is the quality of Calendula extract ensured during the preparation process?

During the preparation process, quality control measures are implemented at multiple stages. Firstly, the quality of the raw materials, Calendula officinalis, is carefully inspected to ensure it is free from contaminants and of the appropriate variety. During extraction, parameters such as solvent concentration, extraction time, and temperature are strictly controlled. After extraction, analytical methods like chromatography can be used to detect the purity and composition of the extract, ensuring it meets the required standards for effectiveness and safety.

5. Can the preparation process of Calendula extract be scaled up for industrial production?

Yes, the preparation process of Calendula extract can be scaled up for industrial production. However, some adjustments need to be made. For example, larger - scale extraction equipment needs to be used, and the control of extraction conditions such as temperature, pressure, and flow rate needs to be more precise. Also, strict quality control systems need to be established to ensure consistent product quality across large - scale production.

Related literature

• Preparation and Characterization of Calendula officinalis Extracts"
• "Optimization of Solvent Extraction of Bioactive Compounds from Calendula officinalis"
• "Quality Control in the Production of Calendula Extract for Cosmetic Applications"