PEG-6 Caprylic/Capric Glycerides CAS 127281-18-9

Introduction to PEG-6 Caprylic/Capric Glycerides

PEG-6 Caprylic/Capric Glycerides is a complex mixture of mono-, di-, and triglycerides and mono- and diesters of polyethylene glycol (PEG) with an average molecular weight of 300, using caprylic (C8) and capric (C10) fatty acids. The molecular architecture combines the lipophilic nature of medium-chain triglycerides with the hydrophilic properties of PEG-6. At room temperature, the compound presents as a pale yellow, transparent, and slightly viscous liquid with a faint characteristic odor. The material is fully miscible with water, ethanol, and most polar organic solvents, while exhibiting excellent solubility in lipophilic oils and fats.

Key Features of PEG-6 Caprylic/Capric Glycerides

• Self-emulsifying capability: Spontaneously forms fine, thermodynamically stable oil-in-water microemulsions upon gentle agitation in aqueous gastrointestinal fluids.
• High HLB profile: The hydrophilic-lipophilic balance of approximately 14 allows seamless integration into aqueous systems to solubilize highly lipophilic compounds.
• Excellent tolerability: Demonstrates a high safety margin for oral and topical administration, causing minimal irritation to the gastrointestinal mucosa or skin barrier.

PEG-6 Caprylic/Capric Glycerides Chemical & Physical Properties

Applications of PEG-6 Caprylic/Capric Glycerides

Oral drug delivery systems: Utilized as the primary surfactant and co-solvent in Self-Microemulsifying Drug Delivery Systems (SMEDDS). When encapsulated in soft gelatin capsules, the excipient rapidly disperses upon contact with gastric fluids, forming a microemulsion that dramatically enhances the absorption and oral bioavailability of highly lipophilic APIs.

Topical and transdermal formulations: Functions as a penetration enhancer and emollient in creams, ointments, and gels. The medium-chain lipid structure fluidizes the stratum corneum, facilitating the deep cutaneous delivery of active pharmaceutical ingredients.

Cosmetics and personal care: Acts as a robust solubilizer for essential oils, fragrances, and oil-soluble vitamins in water-based serums and toners. It prevents phase separation and maintains the crystal-clear optical appearance of the final formulation.

Storage & Safety Precautions for PEG-6 Caprylic/Capric Glycerides

• Temperature and oxidation control: Store in tightly sealed HDPE drums below 25 °C (77 °F). Prolonged exposure to heat and atmospheric oxygen accelerates the autoxidation of the unsaturated lipid fractions, leading to the formation of peroxides and acidic degradation products.
• Handling and PPE: The liquid is a mild eye irritant. Wear safety goggles and nitrile gloves during dispensing.
• Field note: When formulating SMEDDS, pre-blend the lipophilic drug with the oil phase before incorporating PEG-6 Caprylic/Capric Glycerides. This ensures complete molecular dispersion of the API and prevents localized crystallization inside the softgel capsule.

PEG-6 Caprylic/Capric Glycerides FAQ

Q: How does PEG-6 Caprylic/Capric Glycerides improve drug bioavailability?

A: PEG-6 Caprylic/Capric Glycerides acts as a primary surfactant in self-microemulsifying drug delivery systems (SMEDDS). Upon contact with gastrointestinal fluids, it spontaneously forms a fine microemulsion, drastically increasing the surface area for absorption and enhancing the oral bioavailability of highly lipophilic APIs.

Q: Is PEG-6 Caprylic/Capric Glycerides safe for cosmetic formulations?

A: Yes, PEG-6 Caprylic/Capric Glycerides is widely approved for cosmetic and personal care applications. It functions as a mild, non-irritating solubilizer that effectively disperses essential oils and fragrances into water-based serums without causing skin sensitization or leaving a greasy residue.

Q: What causes PEG-6 Caprylic/Capric Glycerides to degrade during storage?

A: PEG-6 Caprylic/Capric Glycerides undergoes autoxidation when exposed to heat, light, and atmospheric oxygen, forming peroxides and free fatty acids. Manufacturers must store the excipient in tightly sealed, opaque HDPE drums below 25 °C to preserve its chemical stability and peroxide value.