The friability test is used to determine, How much percentage of powder or powder is lost from the outer surface of tablets while mechanical and physical handling during transportation. The friability test generally performs on uncoated tablets.
The parallel to friability test, tablets hardness, is also tested to know the strength of tablets which is more important for drugs to withstand throw-out their lifecycle. However, hardness is not only a parameter for tablet strength. Sometimes compressed tablets may lose their crown portion or cap on attrition.
So it is vital to do a friability test to know the percentage of loss powder, which is calculated by using a formula that we have discussed below in this article. As per the formula, the limits of the friability test shall not be more than 1.0%.
Friability test apparatus specifications:
Friability apparatus MOC is a rounded shape drum made of a transparent synthetic polymer with a smooth internal surface. It is Specially designed to minimize static charge. The apparatus comes with a single drum or two drums that are horizontally attached to the axis of the apparatus. The Roche friability apparatus is commonly used for the friability procedure.
Friability apparatus Diameter as per Pharmacopeias:
- Internal diameters: 283.0 to 291.0 mm ( 287.0 ±4.0mm)
- Depth: 36.0 to 40.0 mm ( 38.0±2.0 mm )
- Outer diameters: outer diameter of the central ring is 24.5 to 25.5 mm ( 25.0±0.5 mm )
- The drop height of the friability apparatus is around 6 inches or 156±2.0 mm
- Friability apparatus RPM (revolution/ minutes) = 24 – 26 (25 ±1)
- Total Revolution / Test= 100 Revolutions / 4 Minutes
Responsible person to perform test:
- Production officer/ executive
- IPQA officer
- Quality control officer
Friability Test procedure:
- Collect an equal amount of tablets from both sides of the chute and affix a status label on it. Take the tablet’s weight equal to or less than 6.5 g if the unit weight is equal to or less than 650 mg.
- If tablets have a unit weight of more than 650 mg, then collect ten tablets as a whole sample.
- Check the calibration status before starting the operation.
- Before the test, Dedust all tablets and note down the weight, and put the required quantity of tablets into the drum.
- Set all parameters (revolution time) and start the test.
- After completion, de-dust the whole tablets and weigh them again.
- Now apply the formula to calculate the friability.
- If the result falls out of the accepted limits, repeat the test 3 times and calculate its means.
Note: Proper de-dusting of tablets is to be done before and after the test to avoid false results.
Important: If the shape or size of an uncoated tablet is causing Tambling to be irregular, the friability drum can shift at 10º from the main position.
The formula for friability test use in tablets:
w1= Initial weight of tablets or weight before a test.
w2= Final weight of tablets or weight after the test.
Friability Limits: According to USP, IP and BP, It should be Not more than 1.0%
Calibration of Friability test apparatus:
While using the friability apparatus, We can quickly determine the powder loss from the uncoated tablets’ core surface. Friability tests are beneficial to maintain the quality of solid oral dosage forms (tablets) and further help to know about product stability, which is required for further processing and to transport it.