Glycerin

What is Glycerin?

Glycerin is an ingredient in various products. The wide use of glycerin means it is used in the cosmetic, food, and pharmaceutical industries. The substance is also known as glycerol, which is of vegetable or synthetic origin.

The alkaline hydrolysis of vegetable fats forms vegetable glycerol. As a result of the chemical processes involved in biofuel production, it is obtained in large quantities as a by-product. This chemical substance is odorless and colorless. In a warm environment, it forms a thick, transparent liquid.

Different types of glycerin are used for various goals, depending on their use. Chemicals also play an essential role in the human body. Glycerin is a substance that dissolves very well in water. Its characteristics make the substance a suitable solvent. Glycerin is also a substance with moisturizing and lubricating properties. Due to its properties, glycerol is used to produce medicines and cosmetics. In the food industry, it is used to regulate and maintain the desired moisture of products. Glycerin is considered non-toxic and generally safe for health. However, like every ingredient, it can cause adverse reactions. Learn more about glycerol.

Chemical Properties

Glycerin, glycerol, or glycine alcohol is a three-carbon chain with a hydroxyl group. Glycerol is produced from petrochemical or natural raw materials. It is a substance with low toxicity to humans and the environment. The appearance of glycerol can be described as a colorless liquid that is clear, odorless, and sweet. Glycerol has different boiling and melting points than water. It is a natural solvent that can also undergo a dissolution process.

Substances stored under normal conditions, such as glycerol, are safe and stable, but when they come into contact with oxidizers, they can become dangerous substances that can lead to explosions. Because of this property, glycerol is also used to make explosives, specifically nitroglycerine. Glycerol can undergo various reactions depending on the substances with which it is combined. As such, it can also be used to produce biodiesel. However, the range of uses for glycerol is much broader and also related to medicine and general health.

Uses

Glycerol is an organic molecule that has many uses. Glycerol is 1,2,3-propanetriol, an organic chemical compound from the group of sugars, the simplest stable trihydric alcohol. The molecule can be isolated by heating fats with ash. Glycerol can be used as a raw material in the following industries:

• Cosmetic industry
• Pharmaceutical industry
• Food industry

Cosmetic Industry

In various face creams, lipsticks, and hair conditioners, glycerol is an active ingredient and often forms the product's base. Glycerin is created during the production of soap. The ingredient is commonly used for its moisturizing and occlusive effects. Glycerin strengthens the protective barrier and prevents water from escaping from the epidermis. It belongs to the group of humectants, i.e., substances that prevent drying out.

Glycerol penetrates the stratum corneum, facilitating the transport of different substances into the skin. Glycerin is, therefore, an emulsifier in cosmetics, i.e., it helps to create texture and bind ingredients together. Other glycerol functions in cosmetics include its use as a fragrance ingredient and its preservative action. Its use reduces the multiplication of microorganisms in water, which prevents cosmetics from spoiling.

Pharmaceutical Industry

Glycerol is also used in the pharmaceutical industry. Various types of medicines and pharmaceutical products contain glycerin. These include oral or different kinds of tablets. The organic component makes tablets highly viscous and soluble. Thanks to its extensive hydrogen bonds and hydroxyl groups, glycerol is commonly used to produce tablet coatings.

In addition, glycerol can be found in cleansing preparations or eye drops. Glycerin is also used for various ailments. When administered orally or rectally, it exhibits laxative properties. On the other hand, glycerine solutions applied to the skin soothe irritation and have a solid moisturizing and regenerative effect. Glycerin can also be an ingredient in food supplements.

Food Industry

Naturally, glycerin is found in trace amounts in some fruits and vegetables. Due to its high viscosity, glycerol is added to various food products, such as breakfast cereals and dairy products, in small amounts to thicken the texture. Glycerol is also found in the composition of chocolate products and chewing gum. Other functions of glycerol used in the food industry include regulating and maintaining the desired moisture of products. Binding water also limits the growth of pathogenic microorganisms; thus, like in cosmetics, it can be a preservative. Sometimes glycerin is also used as a sweetener due to its naturally sweet taste.

Benefits

Glycerin is a substance used in various ways due to its properties. Much of its popularity is in the cosmetics industry due to the benefits of using glycerol on the skin. Glycerin also has environmental benefits due to its biodegradability. Different benefits of glycerol include:

• Moisturising properties
• Regenerative properties
• Dissolving properties
• Thickening properties
• Protective properties
• Laxative properties
• Energy properties
• Osmotic properties

Moisturising Properties

Glycerin is mainly known for its intense moisturizing effect. The humectant is responsible for proper hydration and protection against moisture loss in the skin. The substance improves the skin's smoothness and is easy to lubricate due to its high viscosity. Glycerol is added to cosmetics because it does not change in contact with air and holds water. This is why glycerin is often the base of toothpaste, as it prevents hardening and drying out in the tube.

Regenerative Properties

Glycerol can have a regenerative effect that affects the epidermis. Consequently, people also use glycerol to get rid of wrinkles. The ingredient also facilitates the healing of wounds and irritations. As a result, products with glycerin reduce various skin problems. Meanwhile, the substance in hair products has the effect of strengthening the hair and preventing split ends.

Dissolving Properties

Glycerol is a solvent for fats and lipids used to produce creams, lipsticks, and other cosmetic and pharmaceutical products. Glycerol is entirely soluble in substances such as water and alcohol. It dissolves in some substances with a weak effect but cannot dissolve in hydrocarbons. In addition, glycerol can affect the dissolution of different substances, such as bromine, iodine, or phenol.

Thickening Properties

Glycerol is used in various types of products to increase their density. As a food additive, glycerol stabilizes and improves the texture of food. The substance also absorbs moisture and thickens the texture of cosmetics. Glycerol is also suitable for increasing the viscosity of liquid medicines.

Protective Properties

Glycerol acts as a barrier to protect the skin from harmful agents, including wind, cold, and microorganisms. Creams with glycerol can prevent peeling of the epidermis and reduce the feeling of burning and itching. As an additive to cosmetics, the substance prevents the formation of bacteria through its antiseptic action. Glycerin also produces disinfectants, increasing their moisturizing and solubilizing properties and enhancing their antibacterial and antiviral effects.

Laxative Properties

Glycerin can exhibit laxative properties. When administered orally, glycerol stimulates intestinal peristalsis. Also, glycerol applied topically in the suppository type has an irritant effect, promotes intestinal peristalsis, and facilitates bowel movement. Therefore, products with glycerin in these types can be used to treat constipation.

Energy Properties

Glycerin is also naturally produced in the human body. Glycerin is an essential component of triglycerides. Glycerides are esters of a glycerol molecule and an acidic residue of fatty acids. The primary role of triglycerides is to provide energy. Next to glucose, they are the primary energy substrate of the human body. In biological processes, glycerol is involved in metabolizing carbohydrates and lipids. Excess carbohydrates are converted into long-chain fatty acids.

Osmotic Properties

Glycerin is a naturally occurring component in plasma in the human body. Therefore, oral administration of glycerin may have beneficial effects for people with high intraocular pressure. High eye pressure causes various symptoms, such as headaches and visual disturbances.

Elevated open-angle pressure is associated with increased production of aqueous fluid. It can be caused by high blood pressure, glaucoma, or associated with taking selected medications. Glycerol causes water in the body to be drawn into the blood, which results in a reduction in intraocular fluid volume. However, the osmotic effect of glycerol can also contribute to tissue dehydration, but diuresis is low in healthy individuals.

Safety

Glycerol is generally considered a safe substance due to its low toxicity. Glycerol is a natural product that is unlikely to cause allergies. However, with everybody using this product, there is always the possibility of an allergic reaction. It is possible to be allergic to glycerin or a different ingredient in glycerin products. Glycerin is commonly used in cosmetics, medicines, or food, so assessing whether it harms our health and life is necessary. When used in high doses, it can cause side effects. Adverse reactions to glycerin depend on the method of administration.

Oral

When glycerol is administered orally, it is rapidly absorbed from the intestines and stomach and then distributed in the blood. Glycerol can also be found in the ocular fluids, dispersing evenly throughout the body except the cerebrospinal fluid. Finally, the substance is excreted by the kidneys. Synthetic or vegetable glycerin can be safely used in food according to good manufacturing practices.

No signs of toxicity were noted in patients using moderate doses of glycerol when people were given 30 ml of glycerol orally. Glycerol taken orally in excess can cause symptoms such as headache, dizziness, diarrhea, thirst, nausea, and vomiting. Symptoms may result from dehydration, which can be relieved by taking glycerol.

Topical

Glycerol applied topically to the skin is a safe product that rarely causes allergic skin reactions. Even people regularly exposed to glycerin on the skin have not shown any adverse reactions. Glycerin is also not irritating and does not aggravate skin inflammation, making it a safe agent for the skin. Many studies confirm the positive effects of glycerol on the skin and recommend its use even for dry or acne-prone skin.

Ocular

Glycerol can also be used as an ingredient in eye drops. The safety of glycerol related to the eyeballs has been studied. In patients with corneal edema, administration of anhydrous glycerol reduced negative symptoms. However, irritation and pain may occur after administering glycerol directly into the eye. Other side effects include stinging, burning, and increased tear production. However, these side effects do not occur in all patients and may pose a risk.

Availability

Glycerin is widely used in many industries. However, vegetable or synthetic glycerin can be purchased separately from a particular shop or pharmacy. Glycerol is a relatively cheap and generally available substance. Most often, pure glycerin, or with additional substances depending on the product, is available in the type of solution. A glycerin solution can be used for various goals, including health.

Glycerin can be added to cosmetics to increase their moisturizing effect. Glycerol can also be applied directly to the skin, soothing various irritations and inflammations. However, always follow the instructions for the purchased item. If in doubt or symptoms occur, seek the advice of a doctor. Careless use of chemicals, even those with a proven safety record, can adversely affect health, so it is better to minimize this risk.

Summary

Glycerin is a chemical compound, an alcohol with a three-carbon chain. It is used in various industries. Glycerol is often used in the production of cosmetics. In addition, glycerol can be found in food or used to produce medicines. The substance can be of vegetable or synthetic origin. Glycerol has many properties. The most common functions of glycerol include moisturizing and strengthening the skin. Due to its high viscosity, glycerol is added to various food products in small amounts to thicken the texture.

In addition to this, glycerin also occurs naturally in the human body, and it is a component of triglycerides. Glycerin is considered non-toxic and generally safe for health. However, like everybody's ingredient, it can cause adverse reactions. Glycerol is a relatively cheap and typically available substance. Most often, pure glycerin is available in the type of solution.

Sources

• H.W. Tan, A.R. Abdul Aziz, M.K. Aroua (2013). Glycerol production and its applications as a raw material: A review.
  https://www.sciencedirect.com/science/article/abs/pii/S1364032113004127
• Y. N. Min, F. Yan, F. Z. Liu, C. Coto, P. W. Waldroup (2010). Glycerin-A New Energy Source for Poultry.
  https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=cea3891fd189b0e06f3583faf1730fdaf9b05cce
• Lillian C. Becker, Wilma F. Bergfeld, Donald V. Belsito, Ronald A. Hill, Curtis D. Klaassen, Daniel C. Liebler, James G. Marks Jr, Ronald C. Shank, Thomas J. Slaga, Paul W. Snyder, Lillian J. Gill, Bart Heldreth (2019). Safety Assessment of Glycerin as Used in Cosmetics.
  https://journals.sagepub.com/doi/pdf/10.1177/1091581819883820