FIXED OILS

A) Fixed oils

A major class of non aqueous parenteral solvents is the fixed oils. The fixed oils are nonvolatile oils of vegetable origin. The USP recognizes the use of fixed oils as parenteral vehicles and lists their requirements. The fixed oil must never be administered intravenously and are in fact restricted to intramuscular use. Since the fixed oils can be irritating when injected and may cause sensitivity reactions in some patients, thus the oil used in the preparation must be stated on the label. The most commonly used oils for sterile products are corn oil, cottonseed oil, peanut oil and sesame oil. The sesame oil is the preferred oil for most of the official injections in oil due to its high stability (except in light). It usually meets other official requirements.

The USP does not specify specific oil but states that a suitable vegetable oil can used. The main use of such oils is with steroids where they produce a sustained release effect.