Suppositories Flashcards
(41 cards)
What are suppositories?
Solid dosage forms intended for administration of drug via the rectum that melt, soften or dissolve in the body cavity.
What is the typical weight and length of rectal suppositories?
Typically weigh ~2 g and are about 2.5 – 3.75 cm long.
What is the weight of infant suppositories compared to adults?
Infant suppository weight is ~50% of that for adults.
What are vaginal suppositories also known as?
Pessaries.
What is the typical weight of vaginal suppositories?
Weight ~3-5 g.
What are urethral suppositories also referred to as?
Bougies.
What is the typical diameter and length of urethral suppositories for females?
Usually ~5 mm in diameter and 50 mm long.
What is the typical length and weight of urethral suppositories for males?
4 g and 125mm
What are the local applications of suppositories?
Treatment of hemorrhoids, itching, and infections.
What are some systemic applications of suppositories?
- Anti-nauseants
- Anti-asthmatics
- Analgesics
- Hormones
Who are suppositories indicated for?
Infants, small children, severely debilitated patients, those who cannot take medications orally.
Which regions use suppositories more frequently?
Continental Europe (France and Spain) compared to the UK or USA.
What is the pH level of rectal fluid and what’s a feature that needs to be adjusted to work in the rectum?
Neutral (pH 7 – 8), rectal fluid has no buffer capacity therefore suppositories need to be pH adjusted to prevent irritation
What is the traditional fatty base used in suppository formulation?
Oil of Theobroma (cocoa butter).
What is the role of the partition coefficient in suppository formulation?
It is a key parameter influencing drug release rate into rectal fluid.
A drug that is highly soluble in a vehicle has a low leaving tendency and therefore its release rate into the rectal fluid is slow
What is the ideal particle size for drugs in suppositories?
Less than 50 µm to limit local irritation.
What are the ideal properties of a 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 molded and removed from the mold
- Stable when heated above its melting point
- Easy to handle
- Stable on storage
What happens to cocoa butter when melted and cooled?
It solidifies in different crystalline forms.
What are the four different polymorphic forms of cocoa butter?
- α
- β
- β’
- γ
Which polymorphic form of cocoa butter is most stable?
β form.
What is a disadvantage of using cocoa butter in suppositories?
Leakage from the anus may occur since it is immiscible with body fluids.
What is a common solidifying agent added to cocoa butter for hot climates?
Beeswax (4%).
What are hydrogenated vegetable bases also known as?
Hard fat.
What do glyceryl suppositories contain?
14% w/w gelatin + 70% w/w glycerol + water to 100%.
