Suppositories Flashcards
what are suppositories?
solid dosage forms intended for insertion into body orifices where they melt, soften, or dissolve and exert local or systemic effects
what are the most common forms that suppositories are used?
rectally
vaginally
how is shape important with suppositories?
need to be able to be inserted easily into the orifice but stay in place once inserted for the appropriate amount of time
how are rectal suppositories usually inserted?
using the fingers
when would you need an application appliance for vaginal suppositories?
when the insert needs to be inserted high in the tract
what is the usual shape of rectal suppositories?
bullet/torpedo shaped
what is the typical weight for adult rectal suppositories?
2g
what is the typical weight and size of vaginal suppositories?
mass: 5g
cone-shaped or rounded
what are rectal suppositories usually used for (local effect)?
treat pain, inflammation, and itchiness associated with hemorrhoids or other anal/rectal conditions
could also treat constipation
what kind of excipient functions would be found in rectal suppositories for local effect?
local anesthetics vasoconstrictor astringents analgesics emollients protective agents
what agent in suppositories can help treat constipation? how?
glycerin - mild local irritating effect and lubricating effect
what are vaginal inserts typically used for?
contraception
antiseptics for feminine hygiene
local delivery of agents to treat infections (ex: yeast, protozoa)
what are some systemic uses of suppositories?
treat nausea/vomiting
migraine headaches
what are 3 advantages to rectal route for systemic drug delivery?
1) the drugs avoid the pH and enzymatic activity of the stomach and intestine and avoids first-pass hepatic metabolism
2) drugs irritating to the stomach may be given this way
3) useful patients who are unable to take medication by mouth for various reasons including vomiting
what are 2 factors that can affect drug absorption?
physiologic factors
physicochemical factors
how much inert mucous fluid does the rectum contain when empty?
2-3mL
what causes efficient drug absorption in the rectum (physiologically)?
great deal of blood and lymphatic vascularization in the tissue as well as large surface area
how will emptying of colon increase drug absorption?
there will be more contact between released drug and the colon tissues
what conditions could affect rectal drug absorption?
diarrhea
inflammation
tissue dehydration
obstruction by tumours/polyps
why is the drug not affected by the environment of the colon?
empty colon has neutral pH and little buffer capacity
ionic form in which the drug is administered will not be affected by the environment
what 3 properties of drugs affect absorption?
solubility
partition coefficient
particle size
what are 3 properties of suppository bases that affects absorption?
whether it dissolves/melts
whether its hydrophilic/phobic
how it interacts with and releases the drug
what is an important characteristic that make a good suppository base?
remain solid at room temp but soften, melt, or dissolve at body temp
how is cocoa butter as a suppository base?
melts readily at room temp, but is immiscible with body fluids so fat soluble drugs remain in oil rather then enter aqueous body fluids
what substance tends to release fat soluble drugs better?
polyethylene glycol
when is cocoa butter good to use? why?
for inflamed tissues
it has a soothing, emollient action