Experiment 2: Tablet Friability

Title
Tablet Friability
     
Objective

To determine the friability of tablets


Date of Experiment
4th December 2014

Introduction

Tablet friability test is under non-pharmacopoeial standards and is widely used by the manufacturers to know the ability of their product resist to any mechanical shock. The friability of tablet means how easily the tablet being broken up or crumbled. In other words, friability is the phenomenon where the surface of the tablet is damage or shown a site of damage due to mechanical shock. The friability of the tablet also indicates the mechanical strength of the tablet. The mechanical strength of the tablet is usually associated with the resistance of the solid specimen towards fracturing and attrition. For example, the high friable tablet has low mechanical strength and vice versa. This is to ensure that acceptable tablets remain intact during handling process between production and administration. Besides, this test is also used to evaluate the ability of the tablets to withstand the breakage during the transportation.

In our laboratory, this test was carried out by using a machine of Tablet Abration and Friability Tester, TAR-20 (ERWEKA). The friction between the tablet and the drum will cause the abrasion of the tablet and there will be loss of weight at the end of the test. For tablets with a unit weight equal to or less than 650 mg, sample taken as whole tablets corresponding as near as possible to 6.5 g, whereas for tablets with a unit weight of more than 650 mg, the sample taken of 10 whole tablets. Before the operation started, the rate and timing is set. The friability of the tablet is determined from the weight of the total 10 tablets before and after the operation and then calculates the percentage of loss of weight. The percentage of loss of weight of each tablet should not be more than 1% of its weight.

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 are determined.

Materials and Apparatus

Tablets of salbutamol, tablet abration and friability tester machine, Electronic balance, Brush and weighing boat

Procedures

1. 10 tablets of salbutamol is selected and weighed.

2. All 10 tablets are placed into the drum of the Tablet Abration and Friability Tester, TAR-20 (ERWEKA). The rate of rotation is set to 100 rpm, time to 10 minutes and the operation is started. 

   

 

3. At the end of the operation, all the tablets are removed and ensured freedom from dust or powder by using the brush. Then all the tablets are reweighed. The percentage loss of weight is calculated.

   

electronic balance

4. Compressed tablet should nor lose more than 1% of its weight.

Results

Percentage of friability / percentage loss of weight of the tablets of a badge can be find by the following formula:

Percentage Friability = W1 – W2/W1 × 100

Where,

W1 = weight of tablets before testing

W2 = weight of tablets after testing.

Weight of tablets before testing	1.0231 g
Weight of tablets after testing	1.0062 g
The percentage of friability/ Percentage       loss of weight

Discussion

From this friability test, the value of percentage weight loss or the percentage of friability are as much as 1.65%. As we know, the acceptable value should not more than 1% of its original weight. Thus, we could say that our tablets does not pass this test and it need to be improve in such a way that the percentage loss of weight is below than 1%.

We already knew that this friability test is carried out to provide a standardised, reproducible method for measuring the tendency of a tablet to chip or powder when subjected to the mechanical stresses of the manufacturing, packaging and transportation processes of the tablet. Thus, if the tablets does not pass this test, this means that the tablets will not resist to any mechanical shock while transported from one place to another place. So, this tablets need to be remanufacture again to produce a strong tablet but yet still favourable to dissolution and disintegration within the body.

The mechanical strength of tablets is determined by the method used in production of the tablet. Furthermore, excipients of the tablets may contribute to the mechanical strength of tablets. The excipients may include lubricant, glidant, binding agent and diluent. However, the production of tablet which has an optimal mechanical strength is greatly determined by excipients that have been chose in formulation. Besides, the friability of tablet is related to the hardness of the tablets. The higher the hardness of that tablet, the more it resist to mechanical shock and the friability is reduced. However, tablets cannot be too hard because it could reduce the dissolution rate. Friability might also be caused by low moisture content in the tablets and that tablet configuration such as sharp versus beveled edges.

There are some errors may occur during this experiment being conducted. This errors may contribute to the inaccurate result of the experiment (weight loss of tablet).This errors include mistakes of reading from the electronic balance, in which the reading on the electronic balance is being taken before the value shown become stable. Also, result may error due to some dust or powder may still on the surface of the tablet even after the brush have been applied on the tablet when it is weighed.

Conclusion

The salbutamol tablets are not qualified enough to get into the market as the percentage of friability is more than 1%. This shows that it has poor mechanical strength. It also indicates that the entire product has not achieve the standard given by the ministry and does not complied with the GMP.

References

1. http://jpdb.nihs.go.jp/jp14e/14data/Tablet_Friability_Test.pdf
2. http://www.pharma-test.de/friability-testing-manual/
3. http://www.pformulate.com/tablets.htm