What is Friability Test of Tablet ???
Friability is defined as the percentage of weight loss of powder from the surface of the tablets due to mechanical action and the test is performed to measure the weight loss during transportation .
It is a supplement test for Uncoated / Compressed Tablets other than physical measurement e.g. Hardness (Tablet Breaking Force).
Measuring the hardness of a tablet is not a reliable indicator for tablet strength as some formulations when compressed into very hard tablets tend to ‘cap’ or lose their crown portions on attrition. Such tablets tend to powder, chip and fragment.
In friability test the tablets are prone to abrasion hence enabling us to check for the tablet strength under application of force in different manner.
They not only lack elegance and consumer acceptance but also spoil the areas of manufacturing such as coating and packaging.
Who will perform Friability Test ???
- Production ● Quality Assurance (IPQA) ● Quality Control
Friability Drum Specification :
|MOC and Property of Drum||Transparent Synthetic Polymer with polished internal surfaces. Develops minimum Static charge. One side is removable. |
|Drum attachment|| Horizontal to axis of Instrument |
|Internal Diameter|| 283.0 to 291.0 mm (287.0 ± 4.0 mm) |
|Depth|| 36.0 to 40.0 mm (38.0 ± 2.0 mm) |
|Outer Diameter of Central Ring|| 24.5 to 25.5 mm (25.0 ± 0.5 mm) |
|Curved Projection with inside Radius (Extends from middle to outer wallof drum)||75.5 – 85.5 mm (80.5 ± 5.0 mm)|
|Drum Revolution/Minute|| 24 – 26 (25 ± 1) |
|Drop Height|| 154.0 – 158.0 mm (156.0 ± 2.0 mm)|
|Total Revolution / Test|| 100 Revolutions / 4 Minutes |
|Function||At each turn, the Tablets roll or slide and fall onto the drum wall or onto each other|
A drum with dual scooping projections, or apparatus with more than one drum, for the running of multiple samples at one time, are also allowed.
How to perform Friability Test ???
Tablets with unit weight equal to or less than 650 mg, take sample of whole corresponding to as near as 6.5 g equivalent.
Tablets with unit weight more than 650 mg, take sample of 10 whole Tablets.
Tablets must be de-dusted prior to and after test.
Friability (%) =W1 – W2/ W1 X 100
W1 = Weight of Tablets (Initial / Before Tumbling) &
W2 = Weight of Tablets (After Tumbling or friability)
Limit : Friability (%) = Not More Than 1.0 %
Generally, the test is run once.
In case cracked, cleaved, or broken tablets are present in the tablet sample after tumbling, the sample fails the test.
In case the results are difficult to interpret or the weight loss is greater than the targeted value (NMT 1.0 %), the test is repeated twice and the mean of the 3 tests determined. A maximum loss of mass (obtained from a single test or from the mean of 3 tests) NMT 1.0 % is considered acceptable for most products.
Incase Tablet Size or Shape causes Irregular Tumbling & why it happens & What to do :
Tablets bind together when lying next to each other, which prevents them from falling freely.
Adjust the drum base in such a way that the base forms an angle of about 10° with the horizontal surface.
In the case of Hygroscopic Tablets A humidity-controlled environment is required for testing.
Calibration Limit :
|Revolution / Minute||24 to 26 RPM (25 ± 1 RPM)|
|Time / Test|| 3 Minutes & 50 Seconds|
4 Minutes & 10 Seconds
(4 Minutes ± 10 Seconds)