Polyethylene glycol is a commonly used pharmaceutical excipient, and PEG entries are included in the pharmacopoeias of all countries in the world. For a long time, PEG has been widely used in various medicaments such as soft (cream) ointments, suppositories, drops of pills, hard capsules, eye drops, injections, tablets and so on. Since the 1990s, there have been more and more researches on the application of PEG in new pharmaceutical preparations.

Polyethylene glycol is water-soluble and has excellent solubility for many drugs. As an amphiphilic polymer, PEG is soluble in water and most organic solvents, and has the characteristics of good biocompatibility, non-toxicity, and low immunogenicity. It can be excreted through the kidneys. , There will be no accumulation in the body. In addition, PEG has a certain degree of chemical inertness, but it is easy to bond with proteins and other substances after the terminal hydroxyl group is activated. After bonding, PEG can impart many of its excellent properties to the modified substance.

As a surface modification material, polyethylene glycol has the advantages of preventing platelet deposition on the surface of the material when it comes into contact with blood, effectively prolonging the half-life of the modified substance in the body, and improving the drug delivery effect. Adding an appropriate amount of macromolecular PEG to the formulation of solid pharmaceutical preparations such as tablets can increase the fluidity of the drug during tableting, and increase the solubility of the main drug in the stomach, which will ultimately help increase the bioavailability. Therefore, the use of PEG in the pharmaceutical industry has been expanding in recent years.

According to the different degree of polymerization, the use of PEG is different:

1. PEG-400 is most suitable for making soft capsules. Since PEG400 is a liquid, it has wide compatibility with various solvents,
It is a good solvent and solubilizer, and is widely used in liquid preparations, such as oral liquid and eye drops. When vegetable oil is not suitable for active ingredient carrier, PEG is the material of choice. This is mainly because PEG is stable and not easily deteriorated. Injections containing PEG are safe and stable when heated to 150 degrees Celsius. In addition, it can be mixed with high molecular weight PEG, and the mixture has good solubility and good compatibility with drugs.

2. PEG-1450 and 3350 are most suitable for ointment, suppository and cream. Due to the higher water solubility and wider melting point range, PEG1450 and 3350 can be used alone or mixed to produce a storage time field and a melting point range that meets the requirements of drugs and physical effects. Suppositories using PEG bases are less irritating than traditional grease bases.

3. PEG-4000, 6000, 8000 are used in tablets, capsules, film coatings, dripping pills, suppositories, etc.
Due to the plasticity of PEG and its ability to release drugs from tablets in the process of making tablets, high-molecular-weight PEG (PEG4000, PEG6000, PEG8000) is very useful as an adhesive for making tablets. PEG can make the surface of the tablet shiny and smooth, while not easily damaged.

In addition, a small amount of high molecular weight PEG (PEG4000, PEG6000, PEG8000) can prevent the adhesion between sugar-coated tablets and the adhesion between medicine bottles.