Suppository

[1][2][3] 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.

In 1991, a study on suppository insertion in The Lancet found that the "torpedo" shape helps the device to travel internally, increasing its efficacy.

[5] The findings of this single study have been challenged as there is insufficient evidence on which to base clinical practice.

[6] Rectal suppositories are intended for localized or systemic action to relieve pain, constipation, irritation, inflammation, nausea and vomiting, fever, migraines, allergies, and sedation.

[7][8] If they cause inflammation, chronic use of suppositories may cause rectal stricture,[9] but overall this is a safe method of drug delivery.