Polyethylene Glycol (Pharma Grade)

Polyethylene Glycol (PEG), pharma grade, is a synthetic, hydrophilic polymer extensively used in pharmaceutical, biomedical, and cosmetic applications. Known for its non-toxicity, biocompatibility, and solubility, PEG is integral to drug delivery, bioconjugation, and formulation enhancement.

This guide provides a detailed overview of Polyethylene Glycol’s chemical and physical characteristics, key benefits, applications, safety protocols, and environmental considerations.

Chemicals Characteristics

Synonyms: PEG 400, Carbowax, Lutrol
Chemical Formula: H(OCH₂CH₂)ₙOH
CAS Number: 25322-68-3

Molar Weight

380–420 g/mol (PEG 400 example); varies by grade

Melting Point

4–8 °C

Boiling Point

>250 °C

Flash Point

~245 °C

Density

1.11–1.14 g/cc

Forms

Viscous liquid (PEG 400) to waxy solid (PEG 1500+), depending on molecular weights

Entire form

Key Points/Overview

Polyethylene Glycol is valued for its hydrophilicity, non-toxicity, and compatibility with a wide range of active pharmaceutical ingredients (APIs). It acts as a solubiliser, stabiliser, and viscosity modifier in pharmaceutical formulations, enhancing the bioavailability and stability of active compounds.

Its hydrophilic nature supports its use in biomedical applications such as tissue engineering hydrogels and nanoparticle coatings. PEGylation, the process of attaching PEG chains to molecules, improves the pharmacokinetics of drugs by increasing their solubility and circulation time while reducing immunogenicity.

Uses & Benefits

Polyethylene Glycol offers significant advantages across the pharmaceutical, biomedical, and cosmetic sectors. Its versatility, safety, and functional benefits have made it a preferred excipient and active ingredient across these industries, supporting the development of innovative and effective products.

Pharmaceutical Industry

  • Drug Delivery: Enhances the solubility of poorly water-soluble drugs and prolongs circulation time through PEGylation, which reduces renal clearance and increases therapeutic efficacy. PEGylation also minimises the immunogenicity of biologics, leading to safer and longer-acting pharmaceuticals.

  • Excipient: Functions as a binder to provide cohesion in tablet formulations, a lubricant to ease tablet ejection during manufacturing, and a plasticiser to improve the flexibility and durability of solid dosage forms. Its non-toxic and non-irritating nature makes it ideal for oral, topical, and parenteral applications.

  • Topical Preparations: Serves as a humectant in creams and ointments, attracting and retaining moisture in the skin. This improves skin hydration, elasticity, and overall skin health, making PEG a key ingredient in dermatological treatments and cosmetic moisturisers.

Biomedical Applications

  • Bioconjugation: Covalently links to proteins, peptides, and other biomolecules, reducing their immunogenicity and enhancing their solubility, stability, and pharmacokinetics. This application has been critical in advancing biologic drugs and targeted therapies.

  • Tissue Engineering: Forms hydrogels that provide a hydrated, biocompatible matrix for controlled drug release and cell scaffolding. PEG-based hydrogels are widely used in regenerative medicine, wound healing, and drug delivery systems.

Cosmetics

  • Emulsifier: Stabilises oil-in-water and water-in-oil emulsions in lotions, serums, and other cosmetic formulations. This ensures consistent texture, appearance, and performance.

  • Moisturiser: Acts as an effective humectant, attracting water from the environment into the skin. This enhances skin hydration, smoothness, and softness, benefiting a wide range of skincare and haircare products.

Safety Information

Potential Hazards

  • Skin and Eye Irritation: May cause mild irritation; appropriate PPE is recommended.

  • Inhalation: Low risk under normal conditions, though dust from solid PEGs may irritate airways.

  • Ingestion: Generally regarded as safe in regulated quantities but excessive intake may cause gastrointestinal discomfort.

Safety Precautions

  • Personal Protective Equipment (PPE): Use gloves, masks, and safety goggles during handling.

  • Ventilation: Ensure adequate ventilation in areas where PEG aerosols or dust may form.

  • Emergency Response: Rinse affected skin or eyes with water. Seek medical attention if irritation persists.

Storage Recommendations

  • Containers: Store in tightly sealed containers.

  • Conditions: Keep in a cool, dry, well-ventilated area away from direct heat or sunlight.

Occupational Exposure Controls

  • Engineering Controls: Use closed systems or local exhaust ventilation to limit exposure.

  • Administrative Controls: Train personnel in proper handling procedures and emergency responses.

  • Health Surveillance: Monitor employees for signs of skin or respiratory sensitivity.

Environmental Impact and Disposal

  • Environmental Considerations: Generally considered environmentally safe; biodegradable under standard conditions.

  • Disposal Guidelines: Dispose of in accordance with local waste regulations. Avoid releasing large quantities into water systems.

Polyethylene Glycol’s multifunctionality and favourable safety profile make it an indispensable ingredient in pharmaceutical formulations, biomedical devices, and cosmetic products. Compliance with handling protocols and pharmacopeial standards ensures consistent performance and safety across its wide range of applications.