RoA - Rectal/vaginal

Question 1

Rectal advantages

Answer 1

Possible to remove dosage form
Suitable for drugs that will degrade in GI
Suitable for elderly/unable to swallow

Question 2

Rectal disadvantage

Answer 2

Poor patient compliance 
Specialist advice for admin 
May cause local side effects
Manufacturing suppositories is difficult 
Slower absorption than oral

Question 3

Excipients - surface-active agents

Answer 3

Enhance wetting properties of base with rectal fluids

Question 4

Excipients - hygroscopicity reducing agents

Answer 4

May be added in fatty bases to decrease uptake if water

Question 5

Other rectal excipients ?

Answer 5

Mpt controlling agent
Diluents
Adsorbents
Lubricants

Question 6

Vaginal advantages

Answer 6

Can be used for local effect (smaller dose can be used)
Systemic absorption as highly vascular
Suitable for patients with oral restrictions
Self-admin + easy removal

Question 7

Vaginal disadvantages

Answer 7

Gender specific 
For systemic admin.
Hormones/mensuration affect systemic absorption 
Vaginal fluid volume varies
Acidic pH 
Manufacture of vaginal suppositories

Question 8

Why is there lower absorption in the rectum?

Answer 8

Decreases SA of rectum

Question 9

Physiological factors of rectum

Answer 9

3mL of rectal fluid
Neutral pH with minimum buffering
Muscle of rectal wall may influence dissolution
When faeces present means decreased absorption

Question 10

Suppositories bulk?

Answer 10

Fatty base

Water miscible bases (Eg:glycerol-gelatin and polyethene glycol)

Question 11

Different types of vaginal formulations

Answer 11

Tablets
Creams/gels/ointments
Suppositories
Rings

Question 12

Drug release mechanism

Answer 12

Melting at body temp

Disintegration - drugs disintegrate followed by dispersion if contents in vaginal fluids