D. Rectal delivery

Question 1

What is rectal drug delivery ?

Answer 1

Dosage form administered via anus into the rectum or lower colon. Perianal conditions (around the anus)- commonly itching and piles

Question 2

Why is rectal delivery used ?

Answer 2

For a local effect

For a systemic effect- drug absorbed

Question 3

What are the types of dosage forms rectal delivery?

Answer 3

Suppositories
Enemas
Microenemas
Foams, creams, gels, ointments

Question 4

Reasons for rectal route use

Answer 4

Local conditions in rectum and nearby

Oral route is unavailable

GI damage or surgery

Vomiting episode

Sleeping or unconscious patients

Very old or very young or mentally disturbed patients

Drugs with extensive 1st pass metabolism

Convenient night time therapy

Question 5

What are the problems with rectal delivery ?

Answer 5

Not very popular

inconvenient

leakage

Proctitis (rectal inflammation)

Bowel movement

Drug absorption is erratic

Question 6

What are the local uses of rectal administration?

Answer 6

1. Laxative for chronic constipation
2. Bowel evacuation
3. Chronic Bowel disease such as ulcerative colitis, crohns disease
4. inflammation: haemorrhoids, pruitis, proctitis, anal fissures

Question 7

What are the systemic use of rectal administration ?

Answer 7

Pain relief

nausea after chemotherapy

Nausea and vomiting

Arthritis

Seizures

Infections

Question 8

What is the process at which drugs are absorbed in the rectum?

Answer 8

Absorption of unionised drug across the mucosal epithelium

No villi to increase area

Lympthatic absorption also takes place

Rectal veins bypass liver but lower colon vein do not