Quality Control of Suppositories

Each manufactured batch of suppositories must be tested to ascertain whether the required standards are met or not. A visual examination must be carried out for general appearance and suppositories carrying medicaments in suspension should be sliced longitudinally to determine uniform disposition of the medicament.

Assay of the therapeutically active ingredients is also a must to establish whether each unit carries labeled amounts of the drugs or not.

The other necessary tests are the following:

(a)  Determination of the melting range

(b)  Determination of the disintegration/dissolution times

(c)   Fragility assessment

(d)  Drug uptake rates

Determination of the melting range

The melting range determination presents no problem since many melting range devices with high degree of precision are available. This test is necessary only for hydrophobic base suppositories.

Determination of the disintegration/dissolution times

The disintegration and dissolution times can be determined by use of the equipment available for these tests on compressed tablets, with necessary modifications in the test media. Suppositories with water soluble bases are subjected to these tests.

Fragility assessment

Fragility is tested to determine the tensile strength of the suppository to assess whether it will be able to withstand the rigors of normal handling or not.

Drug uptake rates    

Many suppositories carry medicaments for local action and there is no need to carry out drug uptake tests on them. However, those carrying medicaments fro systemic action should necessarily be subjected to in vitro and in vivo tests for drug uptake.

In the in vitro tests the conditions of the test must simulate the situations obtaining in the body cavity.