A suppository is a solid dosage form of medication designed for insertion into a body cavity, where it melts, softens, or dissolves to release its active ingredients. This method of delivery allows medication to be absorbed either locally or into the bloodstream, offering an alternative to oral administration. Understanding the typical appearance and variations of suppositories provides clarity on this less common pharmaceutical form.
Common Physical Characteristics
Suppositories have distinct physical attributes. Their shapes often include conical, torpedo-shaped, cylindrical, or oviform designs, crafted for ease of insertion and retention within body orifices. Tapered or bullet-like forms are common, aiding smooth entry.
These solid forms are typically smooth and firm at room temperature, maintaining their shape until introduced into the body. Their consistency is waxy or greasy due to base materials. Common bases include cocoa butter, which melts readily at body temperature (around 30-36°C), and glycerinated gelatin or polyethylene glycol (PEG), which slowly dissolve in body fluids. Suppositories are usually white, off-white, or translucent, though color varies with the specific active ingredient or base material.
Variations by Type
The form of a suppository is specifically adapted to the anatomical features of its intended insertion site. Rectal suppositories, for example, are commonly torpedo-shaped, conical, or cylindrical, often tapering at one or both ends to aid in placement and retention within the rectum. Adult rectal suppositories typically measure approximately 32 millimeters (about 1.5 inches) in length and weigh around 2 grams. For infants and children, rectal suppositories are usually smaller, often about half the weight and size of adult versions, and may have a more pencil-like shape.
Vaginal suppositories, also known as pessaries, are designed for insertion into the vagina and are often larger than their rectal counterparts. They are typically oviform (egg-shaped), globular, or sometimes cone-shaped, weighing between 3 to 5 grams. This larger, rounded form is suited for the vaginal cavity. In contrast, urethral suppositories, sometimes called bougies, are slender and pencil-like, specifically shaped to fit the urethra. Male urethral suppositories are generally longer, measuring about 140 millimeters (approximately 5.5 inches) with a diameter of 3 to 6 millimeters and weighing about 4 grams, while female urethral suppositories are shorter, around 70 millimeters long and weighing about 2 grams.
Packaging and Handling
Suppositories are typically encased in individual packaging for protection. Common packaging includes foil, plastic, or blister packs. Blister packaging is frequently used and features perforations for easy separation and removal of a single suppository while keeping the others protected.
Proper storage maintains suppository appearance and stability. Many types, particularly those with cocoa butter bases, require refrigeration to prevent premature melting or deformation. If not stored correctly, a suppository can become misshapen or develop an oily appearance. Conversely, some suppositories, especially those made with polyethylene glycol (PEG) bases, are formulated to dissolve rather than melt at body temperature and generally do not require refrigeration, making them more stable at room temperature.