Functional Category
Emollient; oleaginous vehicle; solvent; tablet and capsule lubricant; therapeutic agent.
Applications in Pharmaceutical Formulation
Light mineral oil is used in applications similar to those of mineral oil. It is used primarily as an excipient in topical pharmaceutical formulations where its emollient properties are exploited in ointment bases;(1–3) see Table I. It is also used in ophthalmic formulations.(4,5) Light mineral oil is additionally used in oil-inwater and polyethlylene glycol/glycerol emulsions;(6–9) as a solvent and lubricant in capsules and tablets; as a solvent and penetration enhancer in transdermal preparations;(10) and as the oily medium used in the microencapsulation of many drugs.(11–20) Light mineral oil is also used in cosmetics and certain food products.
Description
Light mineral oil is a transparent, colorless liquid, without fluorescence in daylight. It is practically tasteless and odorless when cold, and has a faint odor when heated. The USP32–NF27 specifies that light mineral oil may contain a suitable stabilizer.
Stability and Storage Conditions
Light mineral oil undergoes oxidation when exposed to heat and light. Oxidation begins with the formation of peroxides, exhibiting an ‘induction period’. Under typical storage conditions, the induction period may take months or years. However, once a trace of peroxide is formed, further oxidation is autocatalytic and proceeds very rapidly. Oxidation results in the formation of aldehydes and organic acids, which impart taste and odor. The USP32–NF27 permits the addition of suitable stabilizers to retard oxidation, butylated hydroxyanisole, butylated hydroxytoluene, and alpha tocopherol being the most commonly used antioxidants. Light mineral oil may be sterilized by dry heat. Light mineral oil should be stored in an airtight container in a cool, dry place and protected from light.
Incompatibilities
Incompatible with strong oxidizing agents.
Safety
Light mineral oil is used in applications similar to those of mineral oil. Mineral oil is considered safe by the FDA for direct use in foods. However, oral ingestion of large doses of light mineral oil or chronic consumption may be harmful. Chronic use may impair appetite and interfere with the absorption of fat-soluble vitamins. It is absorbed to some extent when emulsified, leading to granulomatous reactions. Oral and intranasal use of mineral oil or products containing mineral oil by infants or children is not recommended because of the possible danger of causing lipoid pneumonia.