(Ph. Eur. 11.6 update)
Glycerin Suppositories
DEFINITION
Gelatin………………14g
Glycerol…………….70g
Purified Water A sufficient quantity
In tropical and subtropical countries the quantity of Gelatin may be increased to an amount not exceeding 18 g.
Extemporaneous preparation
The following directions apply.
Add the Gelatin to about 30 mL of Purified Water heated nearly to boiling, then add the Glycerol previously heated to 100° and heat the mixture on a water bath for 15 minutes or until solution is complete. Adjust the weight of the product to 100 g by the addition of hot Purified Water or by evaporation on a water bath and pour into suitable moulds.
The suppositories comply with the requirements stated under Rectal Preparations and with the following requirements.
Content of glycerol, C3H8O3
66.5 to 73.5% w/w.
Disintegration
Maximum time, 1 hour, Appendix XII A2.
ASSAY
Dissolve a number of suppositories containing 8 g of Glycerol in 50 mL of water and add sufficient water to produce 250 mL. To 5 mL add 150 mL of water and 0.25 mL of bromocresol purple solution and neutralise with 0.1M sodium hydroxide VS to the blue colour of the indicator. Add 1.6 g of sodium periodate and allow to stand for 15 minutes. Add 3 mL of propan-1,2-diol, shake, allow to stand for 5 minutes and titrate with 0.1M sodium hydroxide VS to the same blue colour.
Each mL of 0.1M sodium hydroxide VS is equivalent to 9.210 mg of C3H8O3
