What are the main applications of polyethylene glycol(PEG)?


Biomedical Science

Polyethylene glycol and polyethylene glycol fatty acid esters are widely used in the cosmetic and pharmaceutical industries. Because polyethylene glycol has many excellent properties: water-soluble, non-volatile, physiologically inert, mild, lubricating and moisturizing the skin, soft, and pleasant after use. Different relative molecular weight fractions of polyethylene glycol can be selected to change the viscosity, hygroscopicity and organizational structure of the product. Low molecular weight polyethylene glycol (Mr<2000) is suitable for use as a wetting agent and consistency regulator for creams, lotions, toothpaste and shaving cream, etc. It is also suitable for unwashed hair care products. Gives hair a silky shine. Polyethylene glycol with high molecular weight (Mr>2000) is suitable for lipsticks, deodorant sticks, soaps, shaving soaps, foundations and beauty cosmetics. In cleaning agents, polyethylene glycols are also used as suspending and thickening agents. In the pharmaceutical industry, it is used as a base for ointments, creams, ointments, lotions and suppositories.
Polyethylene glycol is widely used in various pharmaceutical formulations such as injections, topical formulations, ophthalmic formulations, oral and rectal formulations. Solid grade polyethylene glycol can be added to liquid polyethylene glycol to adjust viscosity for topical ointment; polyethylene glycol mixture can be used as suppository base; aqueous polyethylene glycol can be used as suspending agent or used to adjust other The viscosity of the suspension medium; polyethylene glycol is used in combination with other emulsifiers to increase the stability of the emulsion. In addition, polyethylene glycol is also used as a film coating agent, a tablet lubricant, a controlled release material, and the like.

Biomedical applications
Medical polyethylene glycol is also known as polyethylene oxide (PEO). Linear polyethers obtained by ring-opening polymerization of ethylene oxide. The main uses in the biomedical field are as follows:
1. Contact lens solution. The viscosity of the aqueous solution of polyethylene glycol is more sensitive to shear rate and bacteria are not easily grown on polyethylene glycol.
2. Synthetic lubricants. Condensation polymer of ethylene oxide and water. In order to prepare the ointment base of water-soluble drugs, it can also be used as a solvent for insoluble drugs such as acetylsalicylic acid, caffeine, nimodipine, etc., for the preparation of injections.
3. The carrier of drug sustained release and immobilized enzyme. Coating the polyethylene glycol aqueous solution on the outer layer of the pill can control the diffusion of the drug in the pill in the body, so as to improve the efficacy.
4. Surface modification of medical polymer materials. The use of polyethylene glycol-containing amphiphilic copolymers to adsorb, trap and graft on the surface of medical polymer materials can improve the biocompatibility of medical polymer materials in contact with blood.
5. Making alkanol contraceptive film.
6. Making hydrophilic anticoagulant polyurethane.
7. Polyethylene glycol 4000 is an osmotic laxative, which can increase the osmotic pressure in the intestinal cavity, absorb water, soften the stool, increase the volume, and promote peristalsis and defecation.
8. Denture fixative. Using polyethylene glycol non-toxic and gelatinous, it is used as a component of denture fixatives.
9. PEG 4000 and PEG 6000 are commonly used to promote cell fusion or protoplast fusion and to facilitate DNA uptake by organisms such as yeast during transformation. PEG can absorb water in solution, so it is also used to concentrate solutions.
10. In experiments on protein molecules, the crowded environment in vivo can be simulated to verify the effect of crowded environment on protein structure

The maximum allowable amount of food additives and the maximum allowable residue standard
Additive Chinese name: polyethylene glycol
The Chinese name of food that is allowed to use this additive: coating of candy and chocolate products
Additive function: coating agent
Maximum allowable use amount (g/kg): use in moderation according to production needs
Maximum allowable residue (g/kg): use in moderation according to production needs

An excellent chemical fusogen for protoplast fusion. It is a polymer of ethylene glycol with the chemical formula HO(CH2CH2O)nH. It is a white yellowish waxy solid, soluble in water, with a slight odor. There are a series of polymers with different relative molecular weights, and those with relative molecular weights between 200 and 6000 can be used as melt enhancers, but those with a relative molecular weight of 1000 are better (it is liquid at this time). PEG is highly water-soluble. In the liquid medium, the ether bond on the surface of its molecule has a weak negative charge. With the participation of Ca2+ ions, the positively charged surface protein or negatively charged glycoprotein can pass through the Ca2+ bridge. connected, so that cells aggregate and fuse. In 50% PEG, the disappearance of free water can lead to dehydration of cells, resulting in changes in the structure of the plasma membrane and cell fusion.
The advantages of PEG for cell fusion are:
①It has strong versatility and can be used in various cells of animals, plants and microorganisms.
②It is easier to prepare and control than Sendai virus.
③Stable activity, easy to use.
weakness is:
① The effective concentration range is narrow (50% to 55%), but it is more toxic to cells at this time.
②The fusion process of cells cannot be observed under the microscope.
③ The frequency of inducing hybrid cells is low (about 1×10-5). In addition to being used as a fusogen, it can also be used to promote the uptake of exogenous transformed DNA by yeast, and can be used as a precipitant in clinical chemistry and an osmotic concentrate for aqueous solutions or suspensions such as serum.

As analytical reagents, also in the pharmaceutical industry
For softeners, lubricants, etc.
It is used as a matrix in medicine and cosmetics, and as a dispersant, lubricant, emulsifier, etc. in rubber, metal processing, pesticide and other industries.
Medium for organic synthesis, humectant for daily cosmetic industry, inorganic salt solubilizer, viscosity modifier, etc.
Used as flocculant, fluid friction reducer, textile sizing agent, retention and drainage aid, binder, thickener and denture fixative, etc.
Used in cosmetics, pharmaceuticals, chemical fibers, rubber, paper, paint, electroplating
Used as casting agent, metal wire drawing, stamping and forming lubricant, paper industry lubricant, cutting fluid, grinding fluid cooling lubrication, polishing agent, etc.
Used as PVC lubricant, masterbatch additive, textile softener, pigment dispersant, etc.
As a papermaking additive, it can improve the retention rate of fillers and fines. When the relative molecular weight is above 3 million, it has good dispersibility, certain wettability, drag reduction and pyrolysis. It is an effective deflocculant. Adding it into pulping can increase the viscosity of the slurry, prevent the fibers from sticking to each other, improve the paper evenness, reduce the power consumption of beating, and improve the physical strength.
PEG-200: It can be used as a medium for organic synthesis and a heat carrier with higher requirements. It is used as a moisturizing agent, inorganic salt solubilizer and viscosity modifier in the daily chemical industry; it is used as a softener and antistatic agent in the textile industry. agent; used as a wetting agent in the paper and pesticide industries.
PEG-400: PEG-400 is most suitable for soft capsules. Because PEG400 is liquid, it has wide compatibility with various solvents, is a good solvent and solubilizer, and is widely used in liquid preparations, such as oral liquids, eye drops, etc. PEG is the material of choice when vegetable oils are not suitable as active ingredient carriers. This is mainly because PEG is stable and not easy to deteriorate, and the injection containing PEG is very safe and stable when heated to 150 degrees Celsius. In addition, it can be mixed with high molecular weight (PEG) and its mixture has good solubility and good compatibility with drugs.
PEG-400, 600, 800: used as a base for medicine and cosmetics, as a lubricant and wetting agent in the rubber industry and textile industry. PEG-600 can be added to the electrolyte in the metal industry to enhance the grinding effect and enhance the luster of the metal surface.
PEG-1450, 3350: PEG-1450, 3350 are most suitable for ointment, suppository and cream. Due to higher water solubility and wider melting point range, PEG1450, 3350 can be used alone or mixed to produce a melting point range that has a long storage time and meets the requirements of drugs and physical effects. Suppositories using PEG bases are less irritating than traditional oleaginous bases.
PEG-1000, PEG-1500: used as matrix or lubricant and softener in medicine, textile and cosmetic industries; used as dispersant in coating industry to improve the water dispersibility and flexibility of resin, the dosage is 10-30 % ; In ink, it can improve the dissolving ability of dyestuff and reduce its volatility. It is especially suitable for wax paper and ink pad ink. It can also be used to adjust ink viscosity in ballpoint pen ink. It is used as dispersant in rubber industry to promote vulcanization. , used as a dispersant for carbon black fillers.
PEG-2000, 3000: used as metalworking casting agent, lubricant and cutting fluid for metal drawing, stamping or forming, grinding, cooling, lubricating and polishing agent, welding agent, etc.; used as lubricant in paper industry, also used as heat Melt adhesive for increased rapid rewetting.
PEG-4000, 6000, 8000: PEG-4000, 6000, 8000 are used in tablets, capsules, film coatings, drop pills, suppositories, etc.
PEG-4000 and 6000 are used as excipients in the pharmaceutical industry for the preparation of suppositories and ointments; as finishing agents in the paper industry to increase the gloss and smoothness of paper; as additives in the rubber industry to increase the lubrication of rubber products It reduces power consumption during processing and prolongs the service life of rubber products.
It is used as a matrix in the industrial production of medicine and cosmetics to adjust the viscosity and melting point; it is used as a lubricant and coolant in the rubber and metal processing industries; it is used as a dispersant and emulsifier in the industrial production of pesticides and pigments; In the textile industry, it is used as an antistatic agent, lubricant, etc.
High molecular weight PEGs (PEG4000, PEG6000, PEG8000) are useful as binders for tablet manufacture due to the plasticity of PEG and its ability to improve the drug release capability of the tablet during tableting. PEG can make the surface of the tablet glossy and smooth without damage. In addition, a small amount of high molecular weight PEG (PEG4000, PEG6000, PEG8000) can prevent the bonding between sugar-coated tablets and the bonding between bottles.
The cell fusion technology mainly adopts polyethylene glycol: polyethylene glycol (PEG) molecules can change the biofilm structure of various cells, so that the lipid molecules of the plasma membrane at the contact point between the two cells are evacuated and reorganized. The mutual affinity of the bilayer plasma membrane and the effect of the mutual surface tension make the cells fuse to form a hybrid cell, and some special hybrid plants can be obtained by culturing the hybrid cell (cytoplasmic hybrid).
Use in molecular biology: PEG can induce the aggregation of macromolecules in aqueous solution. There are many uses in molecular cloning, including: 1. Precipitation of DNA by molecular size; 2. Precipitation and purification of phage particles; 3. Addition of complementary nucleic acids during hybridization, blunt-end ligation of DNA molecules, and DNA end-labeling with T4 polynucleotide kinase chain binding efficiency. 4. Cell or bacterial protoplast fusion.
Polyethylene glycol series products can be used as raw materials for ester surfactants.