What are suppositories?
-They are solid dosage froms administered via the body cavities especially rectum and vagina
What are pessaries?
-Vaginal supossitories
What other dosage forms are used for rectal and vaginal routes?
- Tablets
- Capsules
- Ointments
- Solutions
Provide some ads for rectal route
- When patients cannot use medicine orally
- When drugs are not suitable for oral use
- Can be used for systemic and local delivery
What are some disads for rectal route?
- Poor patient acceptance in some countries
- Sometimes absorption is slow and erratic
- Some excipients may be irritant to the rectum
- Leakage can be a problem
- Stability can be an issue
What are some advantages for vaginal route?
- Can be used for local and systemic delivery
- Avoids harsh stomach environment
- Avoids first pass metabolism of the liver
- Vaginal wall is good for drug absorption
What are some disads for vaginal route?
- It is gender specific
- Leakage is unavoidable
- Patient compliance
- Menstrual cycle and hormonal variations affect absorption
- Some excipients can cause irritation
- Absorption can be affected by pH of the vaginal fluid
The wall of the rectum is smooth and there are no villi. TRUE OR FALSE?
TRUE
What is the pH of mucus in the rectum?
7.5
The lower and middle veins in the rectum drain directly into the systemic circulation, bypassing the liver portal vein. TRUE OR FALSE?
TRUE
The upper veins drains into the liver via the portal vein . TRUE OR FALSE?
TRUE
In which part of the GIshould the suppository be inserted?
Lower part
What factors affect drug absorption from rectum?
- Area of rectal wall is smaller than small intestine
- Quantities of fluid available in the rectum is small
- Properties of the rectal fluid - mostly unknown
- Pressure from rectal wall - helps in spreading and promotes absorption
- No esterase or peptidase activity, hence better stability of peptide drugs
Describe the physiology of the vagina
-A tubular structure connecting the uterus to the external environment coated with vaginal fluid
What is the pH for vaginal fluid?
-Acidic 3.5 - 4.5
The vagina has a rich network of blood vessels leading to inferior vena cava, avoiding the liver portal system. TRUE OR FALSE?
TRUE
What factors affect drug absorption from the vagina?
- Passive/transport
- Age
- The volume, pH and viscosity of vaginal fluid
- Stage of menstrual cycle
- Sexual activity
- Ionisation of drug molecule
- size of drug molecules
Describe the manufacturing of suppositories?
- Melt the base
- Ad drug into the base and mix
- Keep temperature as low as possible
- Pour drug/base mixture into mould, overfill the mould to allow shrinkage on cooling
- Cool at controlled rate to let mixture set
- Scrap of the excess
- Remove the suppositories
How do you maintain quality control?
- Dose uniformity
- Weight uniformity
- Mechanical strength
- Content uniformity
- Disintergration
- Drug dissolution/release
What are the requirements of the vehicles/bases?
- Must melt after inserted into the body or dissolved in fluid cavity
- Melting range should be just below 37 degrees
- Melting range should be small enough for rapid setting when cooled during manufacturing
- During solidification, the base should have enough volume contraction for ease of removal of the suppositories
- The molten base shoudl have suitable viscosity
- Allows satisfactory release
What does the hydroxyl number relate to?
-The amount of mono and diglycerides in the base
What does a high hydroxyl number mean?
- the base is more polar and can absorb more water
- the base tends to have wider melting range
- the base may lead to formation of w/o emulsions which may retard drug release
What does iodine number mean?
-It indicates how unsaturated the base is
When the acid content is high, this is not good. TRUE OR FALSE?
-TRUE
