Castor oil has an unusual fatty acid profile containing modest amounts of both oleic and linoleic acids and 85 to 95% ricinoleic acid (named after Castor itself). It is very thick, pale oil which is one of the reasons it is used so much in cosmetics.
Castor oil is actually soluble in alcohol and creates a unique solubility with beeswax, which is why it is used so much in balms and deodorants. It has a low molecular weight and so penetrates the skin easily, and acts as a softening agent. It is a greasy feeling oil with a lot of shine, but can feel sticky which is why it is used in lipsticks – the added gloss enhances the appearance of the finish and its stickiness helps to keep the oil on your lips without feathering into fine lines. It is low comedogenic (1 out of 5) and non-irritating. It has acanthotic activity, meaning it can help increase skin thickness.
Ricinoleic acid is soluble in alcohol (but not water) and oil. It acts as a humectant and helps make Castor a 'dry'oil as well as increasing its viscosity.
As this is a cold pressed oil, no solvents such as hexane were used in the extraction process.