Sodium PEG-50 hydrogenated castor oil succinate is a chemical compound, a PEG (polyethylene glycol) derivative that has been obtained by a process of etherification and esterification,is the sodium salt of PEG-50 hydrogenated castor oil succinate. 

The name describes the structure of the molecule:

• Sodium is a chemical element with the symbol Na (from the Latin "Natrium") and the atomic number 11. It is a soft, silvery-white, highly reactive metal.
• PEG-50. PEG stands for polyethylene glycol, which is a polyether compound widely used in a variety of applications from industrial production to medicine. "50" refers to the average molecular weight of polyethylene glycol units.
• Hydrogenated Castor oil. Hydrogenation is a chemical process that adds hydrogen to another substance. In this case, the substance is castor oil, a vegetable oil obtained by hot or cold pressing of the seeds of the castor plant. Hydrogenation increases the melting point of the oil, making it solid at room temperature.
• Succinate is a dicarboxylic acid with the chemical formula  (CH₂)₂(CO₂H)₂  involved in several chemical processes in the body, including the citric acid cycle. In this context, it is probably part of a sodium salt.

The synthesis process takes place in different steps:

• Preparation. Castor oil is hydrogenated at high pressure and temperature in the presence of a catalyst, typically a metal such as nickel. This process saturates the unsaturated fatty acids in the oil, resulting in hydrogenated castor oil.
• PEGylation. Hydrogenated castor oil is reacted with polyethylene glycol (PEG) in a process known as pegylation. This process attaches the PEG chains to the oil, increasing its solubility in water.
• Succination.  Pegylate hydrogenated castor oil is reacted with succinic anhydride to introduce succinate groups. This step forms Sodium PEG-50 hydrogenated Castor oil succinate.
• Neutralization. Sodium PEG-50 hydrogenated Castor oil succinate is neutralized with a base such as sodium hydroxide (NaOH) to form the sodium salt, Sodium PEG-50 hydrogenated Castor oil succinate.

What it is used for and where

Sodium PEG-50 hydrogenated castor oil succinate is a complex ingredient used in personal care products. It combines the properties of sodium, PEG-50, hydrogenated castor oil, and succinate.

Cosmetics

Skin conditioning agent - Miscellaneous. This ingredient has the task of modifying the condition of the skin when it is damaged or dry by reducing its flakiness and restoring its elasticity.

Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable. Emulsifiers have the property to reduce the oil/water or water/oil interfacial tension, improve emulsion stability and also directly influence the stability, sensory properties and surface tension of sunscreens by modulating their filmometric performance.

Since the PEG (Polyethylene glycol) family is very large and can be found in cosmetic, industrial, pharmaceutical, medical and other products, it is necessary to make an introductory statement on the subject, which is rather complex from a safety point of view because these products not only come into contact with the skin, but, as in the case of medical products, are ingested.

PEGs (polyethylene glycol) polymerise condensed ethylene oxide and water and are referred to as polyethylene glycols, but in reality they are complex chemical components, polymers bonded together. For example, plastic is polyethylene and has a hard consistency, while polyethylene combined with glycol forms a liquid. PEGylation is produced not only as etherification, but also as transesterification, which is the transformation of an alcohol by an ester. The number appearing after the abbreviation PEG refers to mol of ethylene oxide and the higher this number is, the less it can penetrate the skin.

Safety

 The term 'eth' refers to the ethoxylation reaction with ethylene oxide after which residues of ethylene oxide and 1,4-dioxane, chemical compounds considered carcinogenic, may remain. The degree of safety therefore depends on the degree of purity of the compound obtained. No manufacturer appears to provide this information on the label, at least as of the date of this review.