PEG-60 Hydrogenated castor oil is a chemical compound, polyethylene glycol derived from castor oil with an average of 60 mol of ethylene oxide. Water soluble it is mixed through ethoxylation or hydrogenation of castor oil glycerides and fatty acids, with sixty equivalents of ethylene oxide. and is in the form of a clear, white paste. In the manufacturing process, ethylene oxide is added to the castor oil substrate.

The name defines the structure of the molecule:

• PEG-60 stands for polyethylene glycol, with an average molecular weight of about 60. Polyethylene glycol (PEG) is a polymer composed of ethylene oxide and water that can have different molecular weights depending on how it is synthesised.
• Hydrogenated refers to the process of hydrogenation, in which hydrogen atoms are added to the oil. This process typically converts unsaturated fats into saturated fats, making the oil more stable.
• Castor oil is the oil derived from the seeds of the plant Ricinus communis. Castor oil is a vegetable oil used in different sectors and applications, from pharmaceuticals to cosmetics and food.

Description of raw materials used in production:

• Hydrogenated Castor Oil is derived from castor oil, which is obtained from the seeds of the castor plant (Ricinus communis). The oil is subjected to a hydrogenation process, which involves the addition of hydrogen in the presence of a catalyst to convert the unsaturated fatty acids in castor oil into saturated fatty acids.
• Polyethylene Glycol (PEG)  is a synthetic polymer made by the polymerization of ethylene oxide. It is commonly used in the chemical industry and various applications due to its water solubility and lubricating properties.

The synthesis of PEG-60 hydrogenated castor oil involves the following steps:

• Hydrogenation of castor oil. Castor oil is reacted with hydrogen in the presence of a catalyst to create hydrogenated castor oil. This process increases the oxidative stability of the oil and changes its melting point, making it more suitable for certain applications.
• Reaction with ethylene oxide The hydrogenated castor oil is then reacted with ethylene oxide to create PEG-60 hydrogenated castor oil. The number 60 in the name refers to the average number of ethylene oxide units added per castor oil molecule.

What it is for and where

Cosmetics

Hydrogenated castor oil is a common ingredient in many cosmetic products. While pure castor oil has a penetrating odor, hydrogenated castor oil is odorless.

It is a surfactant, which is a substance that changes the surface tension of liquids. Basically it increases the ability of a liquid to wet and clean, it helps to better clean and slide away particles of dirt, oil etc.

PEG-60 Hydrogenated Castor oil performs the following INCI functions:

• Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable and are used to soothe or soften the skin and emulsify, so they need a specific, stabilising ingredient. This ingredient forms a film, lowers the surface tension and makes two immiscible liquids miscible. A very important factor affecting the stability of the emulsion is the amount of the emulsifying agent. Emulsifiers have the property of reducing the oil/water or water/oil interfacial tension, improving the stability of the emulsion and also directly influencing the stability, sensory properties and surface tension of sunscreens by modulating the filmometric performance.
• Surfactant - Cleansing agent. Cosmetic products used to cleanse the skin utilise the surface-active action that produces a lowering of the surface tension of the stratum corneum, facilitating the removal of dirt and impurities. 

In cosmetic skin products, it can improve transdermal penetration of other detergent chemicals. 

For fragrances, the amount of hydrogenated castor oil used is 2.0 while the ratio of hydrogenated castor oil to solubilized substance is (0.5~3):1. Hydrogenated castor oil can be put into water to solubilize essential oils and synthetic spices.

Applications

Cosmetic and Skin Care Industry:

• Cleansers and Shampoos: Acts as a solubilizer, assisting in blending oily and aqueous ingredients to create a uniform formula.
• Lotions and Creams: Functions as an emulsifier, aiding in combining the water and oil phase.
• Make-up Products: Enhances the texture and spreadability of products like foundation and primers.

Pharmaceuticals:

• Topical Formulations: Boosts the solubility of active ingredients in topical formulations such as creams and ointments.

Household Cleaning Products:

• Cleaners: Acts as a solubilizer, helping disperse oils and dirt, thus improving the cleaning properties of the product.

CAS  61788-85-0

PEG-60 Hydrogenated castor oil studies

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And a premise on PEG.

Since the PEG (1) family is numerous and is found in many cosmetic, cleaning and medicinal products and others, we need a cognitive premise on the subject that is rather complex from the point of view of safety because these products not only come into contact with the skin but, as in the case of medicine, they are also ingested.

PEG or polyethylene glycols polymerise the condensed ethylene oxide and water and are called polyethylene glycols, but in reality, they are complex chemical components, polymers bound together. For example,  plastic is polyethylene and has a hard consistency, while  polyethylene aggregated to the glycol forms a liquid.

The number that appears after the initials PEG represents the molecular weight and the higher this number is, the less it penetrates  the skin. 

Here below are some studies in Medicine that refer to the use of PEG Polyethylene glycol in various fields.

Intestine

Polyethylene glycol with or without electrolytes is effective for the treatment of functional constipation, both in adults and in paediatric patients, with great safety and tolerability. These preparations are the most effective osmotic laxatives (more than lactulose) and are the first-line treatment for functional constipation in the short- and long-term. They are as effective as enemas in faecalomas, avoid the need for hospitalisation and are well tolerated by patients (especially when given without electrolytes) (2).

In the preparation  for colonoscopy,  polyethylene glycol tablets confirmed efficacy, acceptability, tolerance and safety similar to those of sodium phosphate (3).

For peripheral nerve repair (4).

Eyes

Dry eye syndrome is a disorder that affects 5-34% of the world's adult population with reduced quality of life. Artificial or lubricating tears are the most used therapy for treating this condition due to their low side effects profile, which attempt to modify the properties of the tear film. Polyethylene glycol has demonstrated clinical efficacy in the treatment of this condition (5).

Brain

Polyethylene glycol facilitates the neuroprotective effects of magnesium in head injuries (6).

Tumors

For transarterial chemoembolization, Polyethylene glycol is effective and safe for the treatment of liver cancer, as indicated by good tolerability, quality of life and high tumour response (7). 

Cosmetics

Many types of PEG are hydrophilic and are used as creams, topical dermatological preparations and in cosmetic products such as surfactants, emulsifiers, detergents, humectants and skin conditioners.

Safety varies from type to type given the structural complexity (8).

References___________________________________________________________________

(1) Fruijtier-Pölloth C. Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products. Toxicology. 2005 Oct 15;214(1-2):1-38. doi: 10.1016/j.tox.2005.06.001.

(2) Mínguez M, López Higueras A, Júdez J. Use of polyethylene glycol in functional constipation and fecal impaction. Rev Esp Enferm Dig. 2016 Dec;108(12):790-806. doi: 10.17235/reed.2016.4571/2016.

Santos-Jasso KA, Arredondo-García JL, Maza-Vallejos J, Lezama-Del Valle P. Effectiveness of senna vs polyethylene glycol as laxative therapy in children with constipation related to anorectal malformation. J Pediatr Surg. 2017 Jan;52(1):84-88. doi: 10.1016/j.jpedsurg.2016.10.021.

(3) Chaussade S, Schmöcker C, Toulemonde P, Muñoz-Navas M, O'Mahony V, Henri F. Phosphate tablets or polyethylene glycol for preparation to colonoscopy? A multicentre non-inferiority randomized controlled trial. Surg Endosc. 2017 May;31(5):2166-2173. doi: 10.1007/s00464-016-5214-1.
Tsunoda T, Sogo T, Iwasawa K, Umetsu S, Oikawa-Kawamoto M, Inui A, Fujisawa T. Feasibility and safety of bowel cleansing using low-volume polyethylene glycol with ascorbic acid before pediatric colonoscopy: A pilot study. Dig Endosc. 2017 Mar;29(2):160-167. doi: 10.1111/den.12756.

(4) Hoffman AN, Bamba R, Pollins AC, Thayer WP. Analysis of polyethylene glycol (PEG) fusion in cultured neuroblastoma cells via flow cytometry: Techniques & optimization. J Clin Neurosci. 2017 Feb;36:125-128. doi: 10.1016/j.jocn.2016.10.032.

(5) Pérez-Balbuena AL, Ochoa-Tabares JC, Belalcazar-Rey S, Urzúa-Salinas C, Saucedo-Rodríguez LR, Velasco-Ramos R, Suárez-Sánchez RG, Rodríguez-Carrizalez AD, Oregón-Miranda AA. Efficacy of a fixed combination of 0.09 % xanthan gum/0.1 % chondroitin sulfate preservative free vs polyethylene glycol/propylene glycol in subjects with dry eye disease: a multicenter randomized controlled trial. BMC Ophthalmol. 2016 Sep 20;16(1):164. doi: 10.1186/s12886-016-0343-9.

Labetoulle M, Messmer EM, Pisella PJ, Ogundele A, Baudouin C. Safety and efficacy of a hydroxypropyl guar/polyethylene glycol/propylene glycol-based lubricant eye-drop in patients with dry eye. Br J Ophthalmol. 2017 Apr;101(4):487-492. doi: 10.1136/bjophthalmol-2016-308608.

(6) Busingye DS, Turner RJ, Vink R. Combined Magnesium/Polyethylene Glycol Facilitates the Neuroprotective Effects of Magnesium in Traumatic Brain Injury at a Reduced Magnesium Dose. CNS Neurosci Ther. 2016 Oct;22(10):854-9. doi: 10.1111/cns.12591.

(7) Aliberti C, Carandina R, Sarti D, Mulazzani L, Catalano V, Felicioli A, Coschiera P, Fiorentini G. Hepatic Arterial Infusion of Polyethylene Glycol Drug-eluting Beads for Primary and Metastatic Liver Cancer Therapy. Anticancer Res. 2016 Jul;36(7):3515-21.

(8) Jang HJ, Shin CY, Kim KB. Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use. Toxicol Res. 2015 Jun;31(2):105-36. doi: 10.5487/TR.2015.31.2.105.