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

Glycero-gelatin base-contd..

• Less commonly used• Difficult to prepare and handle• Hygroscopic- stringent storage conditions• Incompatible with many drugs• Promote microbial growth

Other examples

• Soap-glycerin• Gelatin replaced with soap• Highly hygroscopic

• Polyethylene Glycols. Commercial manufacture

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

Preparation of suppositories

1.Hand rolling method2.Moulding- hot process or fusion method3.Cold compression method

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.

• 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.

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.

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

Evaluation of suppositories

Displacement value

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

Uses of suppositories

• Local effects• Emollients,astrigents,antibiotics,,steroids,local

anesthetics,hormones• Systemic effects• Analgesics, antispasmodics, antibiotics