- Apparatus:
- Use a drum with an internal diameter between 283-291 mm and a depth between 36-40 mm, of a transparent synthetic polymer with polished internal surfaces and not subject to static build-up as in the figure:
-
- One side of the drum is removable. The tablets are tumbled at each turn off the drum by a curved projection with an inside radius between 75.5 – 85.5 mm that extends from the middle of the drum to the outer wall. The outer diameter of the central ring is between 24.5-25.5 mm. The drum is attached to the horizontal axis of a device that rotates at 25 ± 1 rpm. Thus, at each turn the tablets roll or slide and fall onto the drum wall or onto each other.
- Method:
- Take a sample of whole tablets corresponding as near as possible to 6.50 g for tablets weighing equal to or less than 650 mg.
- For tablets with unit mass of more than 650 mg take a sample of 10 whole tablets.
- Place the tablets on a suitable sieve and remove any loose dust with the aid of air pressure or a soft brush or soft tissue.
- Weight the tablet sample accurately and place the tablets in the drum.
- Rotate the drum by pressing “Enter” which run the drum 100 times (25 rpm for 4 minutes).
- Remove the tablets and remove any loose dust from the tablets as before.
- If no tablets are cracked, cleaved or broken, weigh the tablets to the nearest milligram.
- Generally, the test is run once. If obviously cracked, cleaved, or broken tablets are present in the tablet sample after tumbling, the sample fails the test.
- If the results are difficult to interpret or if the weight loss is greater than the targeted value, the test should be repeated twice and the mean of the three tests determined. A maximum mean weight loss from the three samples of not more than 1.0% is considered acceptable.
- Acceptance criteria:
The loss of mass not more than 1.0 percent and no tablets are cracked, cleaved or broken.
- Expression of the results:
The friability shall be expressed as the loss of mass and it is calculated as a percentage of the initial mass.
