Suppositories and Pessaries Flashcards
What can be absorbed from rectum?
Absorb electrolytes - NA, K, and Cl as faeces pass through.
Absorb water providing hydration and thickens the stool.
What two conditions of the rectum can be treated locally?
Haemorrhoids - steroids, mild astringent, local anaesthetics.
Infection - antibiotics.
Descending colon is accessed by rectal route. What conditions can be treated here?
Constipation - laxatives
Chronic inflammatory diseases = IBS, ulcerative colitis, Crohn’s disease - steroids, amino-salicylates
Describe design of suppositories.
Tapered - aids insertion and retention.
What happens upon insertion of suppository?
- suppository melts/dissolves in rectal fluid.
- drug released into rectum.
- drug dissolved in available fluid - partitioning between liquid base and rectal fluids.
- drug diffuses into cell surface.
- drug exerts therapeutic effect - local/systemic.
Describe properties of an ideal base.
Melts at or just below body temperature (but solid at ambient temperatures) or dissolves in rectal fluid
Non-toxic and non-irritating
Therapeutically inert
Compatible with all drugs, i.e. chemically inert
Physically and chemically stable
Easy to work with
What is barium enema used for?
A barium enema may be performed to diagnose structural or functional abnormalities of the large intestine, including the rectum. These abnormalities may include, but are not limited to: Ulcerative colitis. Ulcerations and inflammation of the large intestine.
Rectal Solutions and Suspensions (Enemas) can be used local treatment of rectum. It can be used to access colon. What can it be used for with access to colon?
- constipation
- bowel cleansing prior to surgery, e.g. Movicol (PEG, osmotic)
- diagnostic, e,g, barium enema
What is a foam?
dispersion of gas in a liquid, stabilised by surfactants
Why might systemic delivery into the vagina be a good idea?
Due to good blood supply - potential for immunisation.
Vaginal drug delivery can access cervix. Why would this be required?
- induction / maintenance of labour
- cervical therapy (CIN)
List why local treatments may be needed for vaginal purposes.
- infections (antibiotics)
- hormone replacement therapy (tissue oestrogenisation)
- specific localised conditions - malignancy
List 3 types of pessaries available.
- all require an applicator device
Vaginal suppositories
Vaginal tablets
Vaginal capsules
Describe vaginal suppositories.
Formulation issues as for rectal suppositories.
Size larger than rectal suppositories (up to 8 g).
Describe vaginal tablets.
Formulation issues as for oral tablets.
Size range wider than for oral tablets.
Tablets disintegrate, drug dissolves in vaginal fluid, diffuses to cell surface, exerts therapeutic effect.
