1. Water soluble & water miscible bases
Glycero- Gelatin base
Mixture of glycerin and water made stiff with the addition of gelatin .
Hydrophilic base- continuous release of medicament.
Vaginal suppositories
Type of gelatin

2. Glycero-gelatin base-contd..
Less commonly used
Difficult to prepare and handle
Hygroscopic- stringent storage conditions
Incompatible with many drugs
Promote microbial growth

3. Other examples Polyethylene Glycols. Commercial manufacture
Soap-glycerin
Gelatin replaced with soap
Highly hygroscopic
Polyethylene Glycols.
Commercial manufacture

4. Emulsifying bases Massa Esterinum- mono,di & triglycerides of FFA
Witepsol- triglycerides of vegetable acids
Massuppol- glyceryl esters of lauric acid
Advantages
Overheating doesn’t alter the physical characteristics
Do not stick to the mould
Solidify rapidly
Less liable to get rancid

5. Preparation of suppositories
Hand rolling method
Moulding- hot process or fusion method
Cold compression method

6. Hot process-fusion method
Thoroughly clean and lubricate the mould place the calculated quantities of powdered/ shredded cocoa butter in adish.Heat the dish on a water bath and when 2/3 of the base melts remove the dish from the bath and stirr until all the base melts
Place the weighed quantity of the medicament to be incorporated on an ointment slab and keep half of the melted base and mix with a flexible spatula.

7. Transfer the mixed mass to the dish and mixed thoroughly so that a uniform mass is formed.
Warm the dish over a water bath for few sec. so that the mass is pourable.Trasfer this melted mass rapidly into the cavities of the mould kept over ice.
When the mass has just set, remove the excess mass with the help of a spatula. Keep the mould in a cool place (10-15’) and open the mould and remove the suppositories.

8. Cold compression method
The mass is prepared by first mixing the powdered drug with an equal quantity of grated cocoa butter and then mixing the remaining amount of grated cocoa butter.
The prepared mass is placed in the cylindrical portion of the machine which is forced to the cavities of the mould through the narrow opening by applying pressure to the piston/handle of the machine thus forming suppositories.

9. Evaluation of suppositories
Check for general appearance, distribution of medicaments, assays of active medicaments.
Uniformity of weight test
Melting range test
Liquefaction time test
Breaking test
Disintegration /dissolution test

10. Evaluation of suppositories
Displacement value
The quantity of the drug which displaces one part of the base is known as displacement value.

11. Uses of suppositories Local effects
Emollients,astrigents,antibiotics,,steroids,local anesthetics,hormones
Systemic effects
Analgesics, antispasmodics, antibiotics