Mainly it is used for testing the consistency of

• Bulk powders before or after compression
• Liquid orals before filling
• Also during filling of powders into capsules or liquids into vials or ampules
• Amount of active pharmaceutical ingredient within individual units of tablets or capsules.

Normally testing is confirmed by performing specific assay to determine the content of drug material contained in particular dosage form.

Content Uniformity Tests: pharmacopoeial comparison

• The International Pharmacopoeia (IP)
• The British Pharmacopoeia (BP)
• The United States Pharmacopoeia (USP)
• The European Pharmacopoeia (Ph. Eur.)

According to United States Pharmacopoeia(USP), the procedure for content uniformity test is
*Stage1: Take 10 units randomly and perform the assay. It passes the test

if the relative standard deviation (RSD) is less than 6% and no value is

outside 85-115%. Fails the test if one or more values are outside

75-125%.

*Stage2: Take 20 more units and perform the assay procedure. Passes the test if RSD of all the 30 tablets is less than 7.8%, not more than one value is

outside 85-115%, and no value is outside75-125%. Or else the batch fails

the test.

Procedure for content uniformity tests according to British pharmacopoeia is as follows

TestA

This test is applicable for tablets, powders for parenteral use and suspensions for injection.

Select 10 units at random. Passes the test if each individual unit is between

85% and 115% of the average content.

Fails the test if more than one individual unit is outside these limits or if even

one is outside the limits of 75% to 125% of the average content. But if

one unit is outside the limits of 85% to115% and within 75%to125%, then

take another 10 units at random and perform the assay.

The lot passes the test if not more than one unit of the thirty units

is outside 85% to 115%, and not even one unit is outside the limits of 75%

to 125% of the average content.

TestB

This method is used for capsules, powders other than for parenteral use,

granules,suppositories and pessaries.

The batch passes the test if not more than one individual unit (out of 10 units

selected at random from a lot) is outside the limits of 85% to 115% and none is outside the limits of 75% to 125% of the labelled content.

The batch fails the test if more than three units are outside the limits of 85%

to 115% or if one or more units are outside the limits of 75% to 125% of the

labelled content.

If two or three units are outside the limits of 85% to 115%, but within the limits of 75% to 125%, then select another 20 units at random. The batch complies the test when not more than three units out of these thirty units are outside the limits of 85% to 115%, and not even one unit is outside the limits of 75% to 125% of the labelled content.

TestC

This test is appicable only for transdermal patches.

The preparation passes test only if the average content of the 10 units is between 90% and 110%, and if the content of each unit is between 75% and 125% of the average content.

References

1. http://www.asi-rtp.com/content_uniformity_testing_.html
2. http://www.docstoc.com/docs/25908598/Content-Uniformity
3. http://www.globepharm.org/what-is-gmp/international-GMPs/drug-quality.html
4. http://www.scribd.com/doc/27605273/Pharmacopoeial-Tests-for-Different-Dosage-Forms