Suppositories

Part of Pharmacy and Apothecary

Solid preparations that melt at body temperature for rectal or vaginal administration — delivering medicine when oral routes are unavailable.

Why This Matters

There are situations where oral medicine is impossible: the patient is vomiting continuously, is unconscious, has severe difficulty swallowing, or has a condition where oral absorption is severely impaired. In these situations, suppositories are one of the few practical alternatives available without injectable equipment. They are inserted rectally (or vaginally for locally-acting preparations), melt at body temperature, and release medicine directly into highly vascular tissue where absorption into the bloodstream is rapid.

The rectal mucosa is richly supplied with blood vessels and absorbs many medications efficiently — often more reliably than the unpredictable absorption of oral preparations in a very ill patient. For fever management in a vomiting child, for severe pain when the patient cannot swallow, for bowel conditions requiring local treatment, suppositories are clinically important.

Making suppositories by hand is straightforward. It requires only a melting base material (cocoa butter or a fat-wax combination), the medicinal substance, and simple molds. Every traditional pharmacist knew how to make them. Every apothecary that treats seriously ill patients should maintain this capability.

Suppository Bases

The base must have specific properties: solid at room temperature, melts at body temperature (around 37°C), non-irritating to mucous membranes, compatible with the medicinal substance, and stable in storage.

Cocoa butter (Theobroma cacao seed fat): The traditional and gold-standard suppository base. Melts at 34-36°C — just below body temperature — releasing medicine reliably and quickly. Non-irritating, compatible with most medicines. A solid at room temperature but melts immediately on contact with skin. Limitation: may melt in warm climates during storage (store in cool location). If cocoa butter is available, it should be the first choice.

Synthetic base alternatives (when cocoa butter is unavailable):

• Tallow (beef fat) + beeswax combination: tallow alone melts around 45°C (too high). Adding beeswax raises the melting point further — the wrong direction. Instead, use tallow alone for a base closer to body temperature. Test each batch for melting point by holding a small piece in the hand.
• Coconut oil: melts around 24°C — too low for warm climates where it will melt before insertion. Usable in cold climates.
• Hydrogenated vegetable oil (if processing capability exists): can be manipulated to desired melting point

Testing melting point: Place a small piece of the prepared (medicine-free) base on your inner wrist. It should melt within 1-2 minutes from body warmth. If it does not melt, it is too firm for use. If it melts immediately when touched with fingers at room temperature, it is too soft.

Calculating the Fill Factor

Medicinal powders do not occupy the same volume as the base material they replace. You cannot simply add 500 mg of powder to a formula designed for 2g of base and expect the correct volume. Each substance has a “fill factor” that tells you how much base to remove per unit of powder added.

Simple method for practitioners without laboratory equipment:

1. Make one batch of pure base (no medicine) and pour into your molds. Allow to set and record the weight of each unit.
2. Make a second batch incorporating your medicine. Record the weight of each unit.
3. If the medicated unit is heavier than the pure base unit, the powder has effectively displaced some base. Adjust accordingly.

For a practical shortcut: most plant powders are slightly less dense than cocoa butter. When adding up to 10% powder by weight, the dimensional difference is small and acceptable. For higher powder loads, reduce base proportionally.

Making Molds

Improvised cone or torpedo molds:

• Roll aluminum foil (if available) into small cones
• Pack smoothed clay around a torpedo-shaped former; fire the clay; use the negative clay forms
• Carve torpedo-shaped grooves into a block of dense wood; wax the interior
• Use a section of bamboo of appropriate internal diameter, cut into lengths

Standard suppository dimensions:

• Adult rectal: approximately 2.5 cm long, 1.5 cm maximum diameter, torpedo shape; weighs approximately 2 grams
• Pediatric rectal: 1.5 cm long, 1 cm diameter; weighs approximately 1 gram
• Vaginal: 2-3 cm long, egg-shaped; weighs approximately 3-4 grams

Making Suppositories: Procedure

Equipment: Double boiler, stirring rod, molds, balance scale, wax paper

1. Prepare molds: lightly coat interior surfaces with tallow or vegetable oil to facilitate release. Chill molds if possible — a cold mold speeds setting.

2. Melt the base in a double boiler until just liquid. Do not overheat — minimum necessary temperature.

3. Remove from heat. Allow to cool until the base is just at melting point — it should be liquid but only barely. This is when you add heat-sensitive medicinal compounds (to avoid destroying them with excess heat).

4. Add the medicinal substance:

   • Powders: incorporate with stirring until uniformly dispersed. Stir continuously — powders settle quickly.
   • Liquid extracts (tinctures): add drop by drop while stirring. Alcohol-based tinctures will make the mixture slightly grainy but workable.
   • Essential oils: add at this stage, stir well.

5. Pour immediately into molds. Fill slightly overfull — the mixture contracts as it cools.

6. Allow to set completely (1-2 hours at room temperature, or 30 minutes if refrigerated).

7. Remove from molds. Trim any excess from the base with a blade.

8. Wrap individually in wax paper or small paper squares. Label the lot.

Key Formulas

Fever suppository (for vomiting patients, especially children):

• 2g cocoa butter base
• 250 mg willow bark powdered extract OR aspirin equivalent if available
• Adult dose: 1-2 suppositories every 6 hours. Child (6-12y): 1 suppository every 6-8 hours

Constipation suppository:

• 2g base
• 0.5 mL glycerin incorporated into the base
• The glycerin irritates rectal mucosa mildly, stimulating evacuation within 30-60 minutes
• Alternatively: a suppository made of 100% glycerin, poured into molds

Hemorrhoid/rectal inflammation treatment:

• 3g base
• 10% witch hazel bark extract (dried extract powder)
• Apply twice daily; the tannins reduce inflammation and bleeding

Vaginal antifungal:

• 4g coconut oil base (coconut oil has intrinsic antifungal activity)
• 5-10% powdered garlic or boric acid (if available)
• Insert nightly for 7 days for vaginal yeast infection

Administration Instructions

For rectal suppositories:

• Patient should have emptied the bowel if possible
• Patient lies on their side with upper knee drawn toward chest
• Lubricate suppository tip with a small amount of oil or wet the tip with water
• Insert blunt end first, as far as finger can reach comfortably
• Patient remains lying for 15-30 minutes to allow the suppository to melt and absorb

For vaginal suppositories:

• Patient lies on their back with knees bent
• Insert as far as possible using a finger
• A simple inserter can be made from a short, smooth wooden stick rounded at one end

Storage: Suppositories must be stored in a cool location or they will melt. In warm climates, store in a cool pit or clay pot in shade. A properly stored suppository retains activity for months.

Do not use suppositories in patients with rectal bleeding of unknown cause, prolapsed rectum, or following rectal surgery. For vaginal use: do not use during pregnancy without specific indication.