Experiment 2 ; Tablet Friability

Title:

Tablet Friability

Objective:

I. To determine physical strength of uncoated tablets upon exposure to mechanical shock and attrition
II. To determine the percentage loss of weight of the tablet after being put into friabilator

Introduction:

                        Friability is the ability of a solid substance to be reduced to smaller pieces with little effort. In pharmaceutical, friability is the tendency for a tablet to chip, crumble or break following compression. This tendency is normally confined to uncoated tablets and surfaces during handling or subsequent storage. Friction and shock are the forces that most often cause tablets to chip, cap or break. The friability test is closely related to tablet hardness and is designed to evaluate the ability of the tablet to withstand abrasion in packaging, handling and shipping. The loss due to abrasion is a measure of the tablet friability. The value is expressed as a percentage. A maximum weight loss of not more than 1% of the weight of the tablets being tested during the friability test is considered generally acceptable and any broken or smashed tablets are not picked up. Normally, when capping occurs, friability values are not calculated. A thick tablet may have less tendency to cap whereas thin tablets of large diameter often show extensive capping, thus indicating that tablets with greater thickness have reduced internal stress

Procedure:

1. 10 tablets of ettrocin are selected and weighed.

2. All the tablets are put into the drum of tablet abration and friability tester. The rate of rotation is set to 25 rpm, time to 10 minutes, and the operation is started.

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

4. The tablets should not lose more than 1% of its weight.

Results:

Initial weight of all tablets = 6.5966 g

Final weight of all tablets = 6.5426 g

% loss of weight = (6.5966-6.5426) X 100 %
6.5966
= 0.82 %

Discussion:

                     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. It can be caused by a number of factors including poor tablet design (too sharp edges), low moisture content and insufficient binder. For obvious reasons, tablets need to be hard enough such that they do not break up in the bottle but friable enough that they disintegrate in the gastrointestinal tract. Tablets prone to capping during the test are considered unfit for commercial use. Friability is affected by various external and internal factors like the punches that are in poor condition or worn at their surface edges, resulting in 'whiskering' at the tablet edge and show higher than normal friability values. Friability test is influenced by internal factors like the moisture content of tablet granules and finished tablets. Moisture at low and acceptable level acts as a binder. In this experiment, the percentage loss of weight of the tablets is 0.82 % which is not exceeding 1 %, the non-pharmacopeia standard. It shows that the tablets are quite able to resist mechanical shock and aberration during the test.

Conclusion:

The percentage loss of weight of the tablets is 0.82 %. Conventional compressed tablets that lose less than 0.5% to 1% of weight are considered acceptable and fit for commercial use.

References:

1. http://www.pharmainfo.net/tablet-evaluation-tests/mechanical-strength-tablets/friability
2. http://www.anabiotec.com/testing/detail/hardness-friability-disintegration
3. http://www.who.int/medicines/publications/pharmacopoeia/TabletFriability_QAS11-414_FINAL_MODIFIED_March2012.pdf