Pharma gyan Pandit

Weight variation test (uniformity of weight)

   Weigh 20 tablet selected at random, each one individually . X1, X2, X3… Xz

Determine the average weight. X= (X1+X2 +X3+…+ Xz)/20

Limit:

Upper limit = average weight + (average weight  % error)

Lower limit = average weight - (average weight  % error)

The individual weights are compared with the upper and lower limits.

Not more than two of the tablets differ from the average weight by more than the % error listed, and no tablet differs by more than double that percentage.

Weight variation tolerances for uncoated tablets

USP -NF standards

SN	Average wt. of tablet(mg)	Max. % difference allowed
1	130 or Less	10%
2	130-324	7.5%
3	More than 324	5%

Indian Pharmacoepia Standards

SN	Average wt. of tablet(mg)	Max. % difference allowed
1	84  or Less	10%
2	84-  250	7.5%
3	More than 250	5%

Content Uniformity Test:

It is an official test. Randomly select 30 tablets. 10 of these assayed individually. The Tablet pass the test if 9 of the 10 tablets must contain not less than 85% and not more than 115% of the labeled drug content and the 10th tablet may not contain less than 75% and more than125 % of the labeled content. If these conditions are not met, remaining 20 tablets assayed individually and none may fall outside of the 85 to 115 % range.