Wonder drug castor oil: The popular oil in industry, medicine & cosmetics
Castor oil is a versatile home remedy that was used thousands of years ago, especially in medicine and cosmetics. Today, castor oil, extracted from the so-called “miracle tree”, enjoys particular popularity in hair and skin care. Learn more about this versatile oil and how to make the most of it in your daily life.
The history of castor oil
Castor oil was already known thousands of years ago. It is mentioned, for example, in the Old Testament, where the book of Jonah (4:6 – 4,7) is written: “Then God the Lord raised a shory shrub over Jonah, which would give shadow to his head and drive out his anger. Jonah was very happy about the castor shrub. But when the dawn came up the next day, God sent a worm that nailed the castor shrub, so that it withered.”
Both the ancient Egyptians, the ancient Greeks and the ancient Romans used castor oil in medicine as a laxative as well as as skin care oil. The oldest mention of castor oil as a medical remedy can be found in the ancient Egyptian papyrus Ebers.
In 1539 the first botanical description of the miracle tree of Hieronymus Bock appeared. In 1582, the physician Adam Lonitzer mentioned the side effects of using castor oil as a laxative. In the Middle Ages, castor oil was mainly used as a fuel until it was used as a laxative again in the middle of the 18th century.
Castor oil is also known by other names. For example, it is known as “Christ palm oil” or “Palmachristi oil”because the leaves are hand-shaped. The name refers to the healing hands of Jesus.
The term“Castor Oil” was coined in English by Peter Canvane, a British physician, in 1764. This name refers to the fact that in Jamaica castor was confused with monk pepper (Agnus castus).
Characteristic features of castor oil
Chemical composition of castor oil
Castor oil consists of a number of fatty acids as well as tocopherol (vitamin E), sterols (membrane fats) and water. The fatty acids contained are:
- Ricinoleic acid (approximately 80-90%)
- Linoleic acid (approximately 4-9%)
- Palmitic acid (approximately 2-8%)
- Stearic acid (approximately 1-4%)
- Eicosenic acid (approximately 0.5%)
- Dihydroxystearic acid (approximately 0.5%)
- Linolea sows (approximately 0.1%)
Properties of castor oil
Optics and consistency
- transparent to yellowish
- oral administration:abdicating
- when used externally:skin care
- combustible from 300° Celsius
- very high density
- very high viscosity (toughness)
- very oxidation-stable
- very polar (electrically not neutral)
- non-dry oil (does not cure in the air)
- soluble in chloroform, ether, ice vinegar and ethanol
- durable for six to eight months when stored dark at room temperature
- tastes and smells unpleasant but mild
Fields of application of castor oil
Castor oil is a versatile product. In most cases, it is processed chemically in order to become usable for the respective area. There are numerous possibilities of chemical modification, which is due to the nature of the main ingredient called triricinolein. This molecule allows many different chemical reactions.
Use of castor oil in medicine
Castor oil was already used in medicine around 1552 BC, as the mention in the ancient Egyptian papyrus Ebers proves. Castor seeds were also found in ancient Egyptian tombs. Also the ancient Greeks and the ancient Romans used castor oil in gastrointestinal complaints.
From the 18th century, the use of castor seeds as laxatives became popular. In this function they were also called “purgier grains”. The ricinoleic acid, which is released in the small intestine and leads to a water accumulation in the intestine, which softens the stool, has a conductive effect. In addition, ricinoleic acid irritates the intestinal wall, which enhances the laxative effect. After taking about 20 ml of castor oil, the first treatment success is already apparent after three to four hours. Overdose can lead to severe diarrhea, nausea, vomiting and severe pain. In addition, side effects may occur due to a lack of intake or increased excretion of important nutrients, vitamins and electrolytes. This includes, for example, an increased efficacy of cardiac glycosides due to the lack of potassium and electrolytes.
In the 1920s, obstetricians began to use castor oil as a blow-promoting and dislieer-free agent to promote and facilitate births. The method of the Oil-Bath-Enema developed: if a pregnant woman exceeded the calculated date of birth, the birth should be initiated by a hot bath and an enema with castor oil. Castor oil as a contraction agent was increasingly used less and less from 1934 after synthetic oxytocins had been developed.
Today, refined castor oil is used for internal and external treatment in medical matters. It is most often added to pharmaceutical products such as sex hormones and eye drops. The application in the labour cocktail, a mixture of various active substances that are supposed to initiate birth pangs, is also very well known. It is also still in use as a laxative.
Externally, castor oil is particularly used against dandruff, age spots, scars, warts and hemorrhoids. The advantage of castor oil is its ability to penetrate deep into the cell spaces.
Application of castor oil in cosmetics
Due to its skin-friendly effect, castor oil is used in creams and bath oils. It is also found in eyelashes, beard, eyelash, lip and hair care products.
It is recommended to use cold-pressed castor oil, also called native castor oil. This has a significantly higher quality and is easily recognizable by the yellowish coloration.
Castor oil in skin care
Castor oil penetrates deep into the cell spaces, stimulates collagen production, which reduces wrinkles, and makes the skin softer.
Castor oil in hair care
In the case of dry, damaged hair, cures with castor oil have a nourishing effect. It also helps against dandruff, provides more volume in the hair and soothes an irritated scalp. For a cure, massage heated castor oil into the hair and scalp, and wash it out thoroughly two hours later.
Application of castor oil in industry
Binders and lubricant
Castor oil is primarily used as a raw material for binders and coatings. In addition, it is often used as a lubricant for motors, as its adhesion to metal surfaces is very good. Castor oil is also found as a lubricant in fuels.
In the past, oil was often used as a fuel, and is now used in the production of biodiesel.
The residues that remain in the production of castor oil are used as fertilizer and animal feed after cleaning.
Use as a method of torture
Since too high a dose of castor oil leads to severe gastrointestinal discomfort, it has unfortunately been and is also used as a torture agent.
Production of castor oil
Castor oil is extracted from the “miracle tree”, in Latin Ricinus communis. The name is misleading because castor is not a tree, but a shrub. It belongs to the wolf-milk family and originally grew up in North Africa and the Middle East. Today, the shrub is found in all tropical regions of the world. The plant grows extremely fast and grows up to six meters in a few months.
The Seeds of the Miracle Tree
The castor oil is obtained from the seeds of the castor shrub. About 1800 seeds are needed to produce one kilogram of castor oil.
Structure of the seed
The seeds consist of three structures:
- Seedling (embryo)The seedling develops from the fertilized egg (zygote) and is still fed by the mother plant.
- Nutrient tissue (endosperm)The nutrient tissue encloses the seedling and feeds the nutrients from the mother plant. It contains about 5% ricin, a toxic protein, and about 0.2% ricinin, another toxic alkaloid.
- Shell (Testa)The shell surrounds the nutrient tissue and the seedling and serves as the outermost protective layer. It is also slightly toxic.
Ingredients of the seed
The castor seeds contain the following substances:
- 55% oil
- 24% protein
- 18% crude fibre
- 3% Ash
Processing into castor oil
Today, the most important producing countries of castor oil are India, China, Brazil and Mozambique. Paraguay, Thailand, South Africa, Vietnam, the Philippines and Angola also account for other shares in the production of the oil. The annual global consumption is about 650,000 tons. The processing is basically carried out in two steps: pressing and refining. Depending on the application area, further processing steps may follow. These are explained in more detail below.
Since the shell of the seeds contains toxic substances, it is first removed.
In the next step, the pressing, the oil is pressed out of the solid components. There are two options:
- Cold pressing (high quality, low yield, high cost) followed by filtering that influences colouring
- Hot pressing (lower quality, high-yield, low cost) followed by refining
Refining means cleaning and finishing. It is only used after hot pressing. Various methods are used:
- Degumming: Here water is added, heated up to 80° Celsius and removed by centrifugation. This is how protein residues are washed out. As a result, the final product no longer contains toxic ricin.
- Use of alkaline solutions: This removes free fatty acids.
- Color optimization: The castor oil is lightened or darkened by the addition of clay minerals or activated carbon.
- Thin film evaporation: The oil is heated thinly to 230° Celsius to remove volatile compounds and odours.
The pressed cake remaining after pressing still contains about 10% castor oil, which can be extracted by chemical processes. However, this resulting castor oil is of rather low quality. The press cake is usually further processed into castor meal, which serves as a fertilizer. By removing the toxins, the press cake can also be used as animal feed.
Special further processing of castor oil
Dehydration of castor oil
During the dehydration of castor oil, water is separated by catalysis, which creates a further double bond between the fatty acids. This turns the oil from non-dry to oxidatively drying oil. Depending on the duration and environment of the chemical reactions, oils of different viscosity develop. The final product produced here is used as a binder for paints, varnishes and linoleum.
Hydrogenation of castor oil
In contrast to deyhdratation, hydrogen is added during the hydrogenation of castor oil, wherein castor wax is produced. This is used both as a component of lubricants and in the soap and cosmetics industry. About 10% of all castor oil produced worldwide is hydrogenated.
Conversion of castor oil
Here, the glycerol of the triglycerides splits off and is replaced by methyl residues. This product is used for the production of biodiesel. However, reesterified castor oil is only partially suitable for this due to viscosity and relative contamination. The fact that it is still used is due to political support, since castor oil is mainly produced by small farmers.
Sulphonation of castor oil
Treatment with sulfur trioxide produces sulfuric acid esters on the molecules. This oil is known as Turkish red oil and is used as a pickle for dyeing textiles.
Alkaline cleavage of castor oil
Alkaline cleavage means adding sodium hydroxide or potassium hydroxide in the presence of alcohols and high temperature. The resulting substances are important raw materials for chemical processing.
Alkoxylation of castor oil
When castor oil is reacted with ethylene oxide or propylene oxide, ethers and substances are produced that are used as lubricants, antistatic agents, emulsifiers or detergents.
Oxidation of castor oil
If castor oil is oxidized in the presence of catalysts in the air or pure oxygen, the oil becomes more viscous and non-migrating. This means that no molecular substances come to the surface of the material, which is why oxidized castor oil serves as a plasticizer for food packaging, for example.
Polyestering of castor oil
When castor oil and citric acid meet, they react together in a polycondensation. Water is split off and a sticky, brown polyester is created.
Pyrolysis of castor oil
If castor oil is decomposed by high temperatures of up to 450° Celsius, fission products are produced, which are needed for the production of flavors and ointments for the treatment of fungal infections and parasitic skin diseases.
Conversion of methanol and castor oil
When converting castor oil with methanol at temperatures of up to 500° Celsius, one of the fission products can be further processed into aminoundecanic acid. This in turn is used for the production of polyamide-11, which is required as plastic for cables, cars and coatings. Polyamide-11 is one of the most important end products derived from castor oil.
Studies on the efficacy of castor oil
In some cases, the efficacy of castor is controversial, but there are some studies in which the efficacy has been proven.
Study results on the laxative effect of castor oil
An example of this is a 2012 study by the Max Planck Institute for Heart and Lung Research in Bad Nauheim. In this, it was demonstrated that a component of castor oil binds to receptors in the muscle cells of the intestine and uterus. The study was led by Stefan Offermanns and Sorin Tunaru. First, they were able to demonstrate that the castor oil ricinacid contained reacted with cell cultures similar to The G-protein-coupled receptors. Gradually, the receptors were deactivated in an exclusion procedure until the receptors that are actually involved in the physical reaction to castor oil could be identified. The G-protein-coupled receptors usually respond to prostaglandin E2. In an experiment with mice whose receptors had been deactivated in genetic manipulations, the effect of castor oil was proven once again. The results of these studies will lead to an increase in the use of castor oil in conventional medicine. In 20. and The 21st century was rather abandoned, as the mechanism of action was not known. With the latest findings, new drugs containing castor oil or the active ingredients in small amounts will be able to be developed in the future, so that the effect will be present, but the side effects will be minimized. More detailed information about this study can be found at:
Study results on the efficacy of castor oil in obstetrics
In 1984, Lorna Davis presented a retrospective study that concluded that the use of castor oil significantly increased the likelihood of birth within 24 hours.
The Ulm castor study also concluded that castor oil can initiate a birth in a small dose. This study can be read after registering under the link: Ulm Castor Study