Polyethylene glycol PEG-2000 is produced by polymerization of ethylene oxide. At room temperature, it appears as a white to slightly yellow waxy solid or flake, with a melting temperature of about 50-55°C. It has good thermal reversibility - it becomes a transparent viscous liquid when heated and melted, and can return to a solid state upon cooling. This property makes it particularly suitable for applications requiring melt processing, such as pharmaceutical suppositories and drop pill matrices.
As a non-ionic polymer, the molecular chain of PEG-2000 has active hydroxyl groups at both ends, endowing it with three core functions: Emulsifying and dispersing ability (can effectively reduce oil-water interfacial tension to form stable emulsions), Wetting and solubilizing effect (significant solubilizing effect on poorly soluble substances), Excellent compatibility (good compatibility with anions, cations, and other non-ionic substances, offering high flexibility in compounding). At the same time, its chemical properties are stable, resistant to acids, alkalis, and hard water, maintaining performance over a wide pH range and under different water quality conditions.
From a safety perspective, PEG-2000 is not classified as a hazardous chemical. The rat oral LD₅₀ is > 2000 mg/kg (often actually > 5000 mg/kg), it is non-irritating to skin and eyes, non-sensitizing, and biodegradable. It is a generally recognized as safe (GRAS) multifunctional excipient. This allows it to be widely used not only in industrial fields but also to meet the high safety requirements of pharmaceutical preparations and cosmetics.
| Parameter | Specification |
|---|---|
| CAS Number | 25322-68-3 |
| Molecular Formula | H(OCH₂CH₂)nOH |
| Average Molecular Weight | Approximately 2000 |
| Appearance | White to slightly yellow waxy solid or flake |
| Melting Point | Approximately 50-55°C |
| Flash Point | > 220°C (Closed cup method) |
| Ion Type | Non-ionic |
| Solubility | Water-soluble |
| GHS Classification | Non-hazardous chemical |
| Recommended Storage Temperature | 5-30°C |
The application of PEG-2000 can be flexibly selected according to industry needs:
When handling molten product, care should be taken to prevent high-temperature burns (melting point about 50-55°C). It is recommended to wear insulating gloves. The operating temperature should be controlled between room temperature and 70°C to avoid local overheating that may cause thermal decomposition. The product should be stored sealed in a cool, dry place, away from strong oxidizers, and protected from direct sunlight. If dust is generated, it is recommended to wear a dust mask and maintain good ventilation in the working environment.