Tablets are prone to
abrasion during transport and handling. Friability test is used to determine
the physical strength or tablet breaking force for compressed, uncoated
tablets. Friability test enabling us to check for the tablet strength under
application of force in different manner.
The friability test
is carried out in an instrument called a friabilator. A friability test
apparatus should stimulate the conditions that the product will be exposed during
the process of production. This test is a method to determine physical strength
of uncoated tablets upon exposure to mechanical shock and attrition.
The commonly used
friabilator in laboratories is the Roche friabilator.
Remove any loose dust
from the tablets and accurately weigh 10 tablets. They are placed in the drum
which rotates at 25±1 rpm. Rotate the drum 100 times, and remove the tablets.
The sample fails the
test, if any of the 10 tablets cracked, cleaved, or broken is present. If the
weight loss is more than 1.0%, the test is repeated for twice and the mean of
three tests is calculated. The mean not more than 1.0% is considered
acceptable.
Please note that for
Effervescent tablets and chewable tablets the friability limits may differ.
If the tablet size or
shape becomes irregular adjust the drum so that base forms an angle of about 10
degrees with bench top and the tablets fall freely when drum is rotated.
