A suppository is a drug delivery system that is inserted into the rectum (rectal suppository), vagina (vaginal suppository) or urethra (urethral suppository), where it dissolves or melts and is absorbed into the blood stream. They are used to deliver both systemically and locally acting medications.
Several different options are used to form the base of a suppository: cocoa butter or a similar substitute, polyethylene glycol, hydrogels and glycerinated gelatin. The ideal type of material to use 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 published a study on suppository insertion in The Lancet, explaining that the "torpedo" shape, when introduced to the patient blunt end first, helps the device to travel internally, increasing its efficacy. The findings of this single study have been challenged as 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.
^Abd-El-Maeboud, K. H.; T. El-Naggar; E. M. M. El-Hawi; S. A. R. Mahmoud; S. Abd-El-Hay (28 September 1991). "Rectal suppository: commonsense and mode of insertion". The Lancet (Elsevier Science) 338 (8770): 798–800. doi:10.1016/0140-6736(91)90676-G. PMID1681170.
^Bradshaw, Ann; Lynda Price (20 December 2006). "Rectal suppository insertion: the reliability of the evidence as a basis for nursing practice". Journal of Clinical Nursing (Blackwell Publishing) 16 (1): 98–103. doi:10.1111/j.1365-2702.2005.01519.x.