A suppository is a solid dosage form that is inserted into the rectum (rectal suppository), vagina (vaginal suppository) or urethra (urethral suppository), where it dissolves or melts and exerts local or systemic effects. Suppositories are used to deliver both systemically and locally acting medications.
Several different ingredients can be used to form the base of a suppository: cocoa butter or a similar substitute, polyethylene glycol, hydrogels and glycerinated gelatin. The type of material used depends on the type of suppository, the type of drug and the conditions in which the suppository will be stored.
In 1991, Abd-El-Maeboud and his colleagues conducted a study on suppository insertion in The Lancet, explaining that the "torpedo" shape helps the device to travel internally, increasing its efficacy. The findings of this single study have been challenged as there is insufficient evidence on which to base clinical practice.
Alprostadil pellets are urethral suppositories used for the treatment of severe erectile dysfunction. They are marketed under the name Muse in the United States. Its use has diminished since the development of oral impotence medications.