Introduction to Suppositories
Objective
At the end of this lecture, student will be
able to:
·
Discuss suppositories and its application
·
List advantages and disadvantages of suppositories
·
Explain suppositories types
·
List the ideal properties of suppositories bases
Suppositories
q These are unit solid preparations
which are intended for insertion into the body cavities like rectum, vagina,
urethra, nose or ear cavity.
q They are normally used for local
action or systemic absorption of the active ingredient.
q They usually melt, soften, or
dissolve at body temperature and release the drug into body.
q They may contain one or more active
medicaments
Applications of Suppositories
Mechanical action
q
Suppositories
are extensively used as a mechanical aid to bowel evacuation which produce its
action by either irritating the mucous membrane of the rectum (e.g. glycerol
and bisacodyl) or by lubricating action or by mechanical lubrication.
q They have been used for a variety of
conditions like hemorrhoids and local infections in vagina and rectum.
Local action
q The suppositories may be used for
soothing e.g. zinc oxide, local anaesthetic- e.g. cinchocaine,
benzocaine,astringents e.g. bismuth subgallate, hamamelis extract and tannic
acid, anti-inflammatory e.g. hydrocortisone and its acetate.
q It
is the alternated dosage form for drugs which have less bioavailability when it
is taken orally
To provide systemic action
q Suppositories are convenient mode of
administration of drugs which irritate the gastrointestinal tract, cause
vomiting, destroyed by the hepatic circulation or destroyed in the stomach by pH changes,
enzymes etc.
q Drugs
having bad odour and taste can be used in suppository form.
q It
is suitable for unconscious patients.
q It is suitable for drugs irritating effect in
GIT.
q It
is suitable for infants and old people who find difficulty in swallowing of
drugs.
q It
is suitable for the drugs which are destroyed by portal circulation.
Disadvantage of Suppositories
q The
manufacturing process is more difficult as compare to other formulation.
q The
drugs which cause irritation to mucous membrane cannot be administrated by this
form.
q Incomplete
absorption may be obtained because suppository usually promotes evacuation of
the bowel.
q Suppositories
are not suitable for patients suffering from diarrhea.
Types of Suppositories
1. Rectal suppositories
2. Vaginal suppositories
(Pessaries)
3. Urethral Suppositories (Urethral
bougies)
4. Nasal suppositories (Nasal
bougies)
5. Ear cones (aurinaria)
Rectal suppositories
q These are meant for introduction into
the rectum for their local or systemic effect.
q They are tapered at one or both ends
and usually weigh about 2 g and for children are smaller in size with weight of
1 g.
q Rectal
suppositories intended for localized action are most frequently used to relieve
constipation or the pain, irritation, itching, and inflammation associated with
hemorrhoids or other anorectal conditions.
Vaginal suppositories
(Pessaries)
q They are meant for introduction into
vagina.
q They are larger than rectal
suppositories and vary in weight from 3 to 6 g or more.
q They may be conical, rod-shaped or
wedge shaped.
q They are exclusively used for their
local action on vagina.
q Localized
effects are employed mainly as contraceptives, antiseptics in feminine hygiene,
and as specific agents to combat as invading pathogen.
Urethral Suppositories
(Urethral bougies)
q They are meant for introduction into
the urethra.
q Their weight varies from 2 to 4 g
and length from 2 to 5 inch.
q Urethral suppositories are very
rarely used.
Nasal suppositories (Nasal
bougies)
q They are meant for introduction into
nasal cavity.
q They are similar in shape to urethral bougies.
q Their weight is about 1 g and length 9-10 cm.
q They are always prepared with
glycero-gelatin base.
Ear cones (aurinaria)
q They are meant for introduction into
the ear.
q Generally theobroma oil is used as a
base.
q They are prepared in an urethral
bougies mould and cut according to the required size.
Properties of an ideal
suppositories base
1. It
should melt at body temperature or dissolve or disperse in body fluids.
2. It
should release the medicament readily.
3. It
should retain its shape during handling, transportation and storage.
4. It
should be non-toxic and non-irritant to the mucous membrane.
5. It
should be stable on storage.
6. It
should be compatible with any added medicament or additives.
7. It
should be stable if heated above its melting point.
8. It
should be easily moulded and should not adhere to the mould.
9. It
should not produce any pharmacological action.
Types of Suppository Bases
I. Fatty
Bases (Oleaginous Bases)
Theobroma oil (Cocoa
butter)
Synthetic fats
II. Water Soluble and Water Miscible Bases
Glycero-Gelatin base
Soap-Glycerin Suppositories
III. Emulsifying Bases
Witepsol
Massa Esterium
Massuppol
Ideal
Suppository Base
• Melts
at body temperature or dissolves in body fluids.
• Non-toxic
and non-irritant.
• Compatible
with any medicament.
• Releases any medicament readily.
• Easily moulded and removed from the mould.
• Stable
to heating above the melting point.
• Easy
to handle.
• Stable
on storage.
Summary
q Suppositories are unit solid
preparations which are intended for insertion into the body cavities like
rectum, vagina, urethra, nose or ear cavity.
q Pessaries, Urethral bougies, Nasal
bougies, aurinaria, Rectal suppositories are the types of suppositories.
Types of
Suppository Bases
q Fatty Bases (Oleaginous Bases)
Theobroma oil (Cocoa
butter)
Synthetic fats
q Water Soluble and Water Miscible
Bases
Glycero-Gelatin base
Soap-Glycerin
Suppositories
q Emulsifying Bases
Witepsol
Massa Esterium
Massuppol