OBJECTIVE
To determine the friability of tablets and its ability to withstand abrasion.
INTRODUCTION
Friability is the tendency for a tablet to chip, crumble or break following compression. This tendency is normally due to uncoated tablets and surfaces during handling or subsequent storage. Tablets are constantly subjected to mechanical shocks and aberration to manufacturing, packing and transportation process. Such stress can lead to capping, aberration or even breakage of tablets
It is usually caused by a number of factors including poor tablet design (too sharp edges), low moisture content,and insufficient binder. 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.
Based on an original design by Roche, the friability tester has now become an accepted standard throughout the pharmaceutical industry for determining the resistance of uncoated tablets to the abrasion and shock experienced in manufacturing, packing and shipping operations.
PROCEDURES
1. 10 tablets were selected and weighed.
2. All tablets were put into drum of the tablet abration and friability tester. The rate was set at 100 rpm rotation, time to 10 minutes and the operation was started.
3. At the end of operation, all the tablets were removed and freedom was ensured from dust or powder (use the brush). The tablets were reweighed. The percentage lost of weight was determined.
4. Compressed tablets should not lose more than 1% of its weight.
RESULT AND CALCULATION
Drug : Methyldopa tablets 250 mg.
Initial result : 3.5262 g
Final result : 3.5086 g
Loss of weight : 0.0176 g
Percentage of loss weight of methyldopa tablet : (0.0176/ 3.5086) x 100% = 0.5 %
Hence, the percentage of loss weight after tablet abration and friability tester is less than 1 %.
Before test:
Before test:
After test :
DISCUSSION
In this, tablet friability experiment, 10 250mg methyldopa tablets were selected and weighed before it was put into drum of the tablet abrasion and friability tester. The speed for the rate of rotation is 25 rpm and it was done for 25 minutes. In order to determine the friability of tablets and its ability to withstand abrasion, tablets are weighed and the weight compared with initial weight. The loss due to abrasion is measure of tablet friability. The value is expressed in percentage. Minimum weight loss of the tablet should not be more 1%. There should not be any broken tablet. The higher the amount of weight loss, the more fragile are the tablets.
For this experiment, the percentage loss of weight is 0.5 % .Since, the percentage loss of weight is less than 1 %, the tablet has good friability for compressed tablet. 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. Effervescent tablets and chewable tablets may have different specifications as far as friability is concerned
CONCLUSION
In conclusion, the weight loss of tablet methyldopa 250 mg is 0.076 g which means that the tablets are strong and hard enough to prevent breaking during the packing, handling and also shipping. The tablets are able to withstand the abrasion.
REFERENCES
1. http://www.pharmainfo.net/tablet-evaluation-tests/mechanical-strength-tablets/friability
2. http://www.pharmainfo.net/tablet-evaluation-tests/mechanical-strength-tablets/friability
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