🔹 SUPPOSITORIES
Definition
Solid, medicated preparations designed for insertion into the rectum, where they:
o Melt, dissolve, or disperse
o Exert a local or systemic effect
General Characteristics
Solid, single-dose preparations
Shape, volume, and consistency suited for rectal administration
Contain one or more active substances dispersed or dissolved in a suitable base
The base may be:
o Water-soluble/dispersible, or
o Melting at body temperature
May contain diluents, adsorbents, surfactants, lubricants, preservatives, and coloring
agents
Preparation
Usually prepared extemporaneously by pouring molten mass into molds
Common shapes: rounded cone, bullet, or torpedo
🔹 PESSARIES
Definition
Solid medicated preparations for insertion into the vagina, usually to exert a local
effect.
Characteristics
Solid, single-dose preparations
Usually ovoid or cone-shaped, with a suitable volume and consistency
Contain one or more active substances dispersed/dissolved in a suitable base (similar to
suppositories)
Types and Use
Moulded like suppositories, using 4 g or 8 g moulds
Mainly used for local medication
o Exception: Prostaglandin pessaries → systemic effect
Common ingredients:
Antiseptics
Contraceptive agents
Local anaesthetics
🌿 ADVANTAGES OF SUPPOSITORIES
1. Provide local effects on rectal mucosa (e.g., anaesthetic, anti-inflammatory).
2. Promote bowel evacuation (laxative suppositories).
3. Avoid gastrointestinal irritation caused by oral drugs.
4. Useful for unconscious, vomiting, or fitting patients.
5. Enable systemic absorption while avoiding first-pass metabolism by the liver.
⚠️ DISADVANTAGES
1. May be unacceptable to certain patients or cultures.
2. Difficult to self-administer for arthritic or disabled patients.
3. May show variable or unpredictable absorption in vivo.
️ PROPERTIES OF AN IDEAL SUPPOSITORY BASE
Melts at body temperature or dissolves in body fluids
Non-toxic and non-irritant
Compatible with medicaments
Releases medicament readily
Easily moulded and removed
Stable to heating and on storage
Non-sticky, easy to handle
💧 TYPES OF BASES
1. Water-Soluble / Water-Miscible Bases
Examples:
Glycero-gelatin base
Macrogols (Polyethylene glycols)
A. Glycero-Gelatin Bases
Contain glycerol + gelatin + water
Have a laxative effect
Hygroscopic → absorb atmospheric moisture
Must be protected from humidity
May irritate tissues → moisten before insertion to reduce irritation
More time-consuming to prepare than fatty bases
Difficult to remove from mold → lubrication is essential
B. Macrogols (Polyethylene Glycols)
No physiological or laxative effect
Resist microbial contamination
Absorb water, forming a viscous solution → less leakage
High melting point → dissolve rather than melt → sustained effect
Contract on cooling → no lubrication needed
Hygroscopic → must be stored carefully
May irritate rectal mucosa
Can become brittle if cooled too quickly
⚗️ OTHER ADDITIVES
Antioxidants: Prevent oxidation of base or drug
Preservatives: Prevent microbial growth
Emulsifiers: Help incorporate aqueous solutions
Hardening agents: Increase melting point
Viscosity modifiers: Reduce sedimentation of insoluble medicaments
️ CALCULATIONS AND EXCESS
Always prepare extra quantity to account for wastage during molding.
o Example: If 6 suppositories required → calculate for 10 suppositories.
⚙️ SHAPES AND WEIGHTS
Average
Type Shape Remarks
Weight
Rectal Suppository (Adult) Bullet/Torpedo ~2 g Tapered for easy insertion
Child Suppository Longer, narrower ~1 g Half adult weight
Vaginal Suppository Globular, oviform, cone- Inserted high with
3–5 g
(Pessary) shaped applicator
⚡ ACTIONS
Local Action
Acts directly on site of insertion.
Examples:
Soothing inflamed hemorrhoids
Promoting laxation
Antiseptic or contraceptive pessaries
Systemic Action
Drug absorbed via mucosa into systemic circulation.
Used for:
Asthma
Nausea
Motion sickness
Anxiety
Bacterial infections
️ SUPPOSITORY MOULDS
Metal, plastic, or disposable molds used.
Ensure uniform shape and volume.
Mould lubrication may be required depending on base type.
️ SHELF LIFE AND STORAGE
Generally stable if properly stored at cool temperature.
Expiry: ~3 months (in absence of official guidance).
Commercial products carry manufacturer’s expiry date.
📦 DISPENSING AND PACKAGING
Base Type Recommended Packaging Notes
Tightly closed, wide-mouthed Hygroscopic — protect from
Glycerin / Glycerinated Gelatin
glass bottles moisture
Cocoa Butter / Carbowax Cardboard boxes with partitions Prevent sticking or deformation
Foil-wrapped Plain boxes or jars No partitions needed
Metal mould products Wrapped in aluminium foil Can be stored in jars/cartons
Ensure patient can easily release
Disposable moulds Dispensed directly
the suppository
Volatile ingredient (e.g. Wide-mouthed, tightly closed
Prevent loss of volatile component
menthol, phenol) glass bottles
🏷️ LABELING & PATIENT ADVICE
General Directions:
Indicate site of insertion clearly.
Include storage conditions and warnings.
Examples of Label Statements:
“For rectal use only”
“For vaginal use only”
“Store in a cool place (below 15°C)”
“Remove foil wrapping before insertion”
️ SUMMARY TABLE
Category Suppositories Pessaries
Site of insertion Rectum Vagina
Typical weight 1–2 g 3–5 g
Shape Bullet/Torpedo Ovoid/Cone
Main use Local/systemic effect Local effect
Base types Fatty, glycero-gelatin, macrogol Same
Label “For rectal use only” “For vaginal use only”
