A tablet’s strength has a significant impact on its marketing, transportation and dissolution. The mechanical strength of tablet or granules can be determined by its hardness and through friability test.
A clear synthetic polymer drum with polished internal surfaces that is not susceptible to static buildup shouldbe used; it should have an internal diameter of 283 to 291 mm and a depth of 36 to 40 mm. The drum has a detachable side. A curving projection that runs from the center of the drum to the outside wall and has an inside radius of 75.5 to 85.5 mm tumbles the tablets with each rotation of the drum. A device that revolves at 25 ±1 rpm has the drum fixed to its horizontal axis. As a result, the tablets slide or roll during every rotation, landing on the drum wall or one another.
Friability test procedure and Acceptance Criteria
- A sample of 6.5 g tablets should be taken for tablets with a unit mass of 650 mg or less.
- A sample of 10 tablets should be taken for tablets with a unit mass of more than 650 mg
- Prior to testing, the tablets should be thoroughly dedusted.
- Weigh the tablet sample precisely, then put the tablets in the drum.
- Rotate the drum 100 times and remove the tablets.
- Remove any loose dust from the tablets as before and accurately weigh. Generally, the test is run once.
- If any cracked, cleaved, or broken tablets are present in the tablet sample after tumbling, the sample fails the test.
- If the results are doubtful 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 for most products.
- If tablet size or shape causes irregular tumbling, adjust the drum base so that the base forms an angle of about 10 with the bench top and the tablets no longer bind together when lying next to each other, which prevents them from falling freely.
- Effervescent tablets and chewable tablets may have different specifications as far as Friability is concerned. In the case of hygroscopic tablets, an appropriate humidity controlled environment is required for testing.