Ceresin is a white-to-yellow waxy mixture of hydrocarbons obtained by purification of ozokerite. It occurs as odorless, tasteless, amorphous (noncrystalline) brittle, waxy cakes or pastilles.
Cera mineralis alba; ceresine; ceresine wax; ceresin wax; cerin; cerosin; Cirashine CS; earth wax; GS-Ceresin; Koster Keunen Ceresine; mineral wax; purified ozokerite; Ross Ceresine Wax; white ceresin wax; white ozokerite wax.
Chemical Name and CAS Registry Number: Ceresin [8001-75-0]
Empirical Formula and Molecular Weight
Ceresin is a mineral wax composed of a wide and complex range of long-chain, high-molecular-weight, saturated and unsaturated hydrocarbons, ranging from C20 to C32.
Functional Category: Coating agent; opacifier; stabilizing agent; stiffening agent.
Applications in Pharmaceutical Formulation or Technology
Ceresin is used as a stiffening agent in creams and ointments and as an emulsion stabilizer, opacifier, viscosity control agent, and thickener in pharmaceutical protective, topical, and vaginal creams. It is also used in cosmetics and personal care products.
Ceresin is often used as a substitute for ozokerite wax due to its similar properties, and also as a substitute for beeswax and paraffin wax. It acts as a rheological modifier at low concentrations (2–3%) and has the ability to create very small crystallites, which crosslink and establish a network structure that does not allow flow in practical conditions. Ceresin produces stable mixtures with oils and prevents bleeding or sweating of oil, and it produces a lighter cream that is less greasy.
Ceresin is also used for pharmaceutical coating applications of medicaments, for example, protective coatings, enteric coatings, and sustained-release coatings. It has been used in the formulation of multivesicular emulsion topical delivery systems.
Method of Manufacture
Ceresin is prepared by extraction and purification of the native mineral fossil wax ozokerite, which is derived from coal and shale. Ozokerite is mined from deposits in various localities around the world. It is found as irregular mineral veins or as a black mass in clay strata. Mined ozokerite is heated to melt it, and any earth or rock is removed. If necessary, it is heated to 115–1208C to remove any moisture and then treated with sulfuric acid or fuming sulfuric acid.
After neutralization, it is decolorized using activated charcoal or silica gel, and filtered. If decolorizing is not sufficient, it is repeatedly treated with sulfuric acid and subjected to adsorption filtration to produce more refined ceresin. Another method of producing ceresin involves dissolving ozokerite in ligroin, treating it with activated clay, and then removing the high-boiling-point fraction