Chemical Properties
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.
Definition
CERESIN WAX is a complex combination of hydrocarbons produced by the purification of ozocerite with sulfuric acid and filtration through bone black to form waxy cakes.
Production Methods
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 115–1208℃ 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.
Pharmaceutical Applications
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.
Safety
Ceresin is nontoxic, nonhazardous, and safe for use in personal care
and cosmetic ingredients in the present practices of concentration
and use. The Cosmetic Ingredient Review Expert Panel has
concluded that ceresin does not result in dermal sensitization.
When formulations containing these ingredients were tested, they
produced no skin irritation and the formulations were not
phototoxic.
Ceresin may be slightly hazardous on ingestion and inhalation. No definitive information is available on carcinogenicity,
mutagenicity, target organs, or developmental toxicity. The FDA
has established a cumulative estimated daily intake of ceresin of
0.00035 mg/kg body weight, and a cumulative dietary concentration
in food of not more than 7 ppb.
storage
Ceresin should be stored in well-closed containers in a cool, dry,
well-ventilated place, away from extreme heat and strong oxidizing
agents.
Incompatibilities
Ceresin is incompatible with strong oxidizing agents. It is
compatible with most animal, vegetable, and mineral waxes, as
well as mineral oil and petrolatum.
Regulatory Status
Included in the FDA Inactive Ingredients Database (topical
ointments; vaginal emulsions and creams). Included in the
Canadian List of Acceptable Non-medicinal Ingredients. Included
in nonparenteral medicines (topical creams) licensed in the UK.
Accepted for use in cosmetics and personal care products marketed
in Europe.