Practical 3 (1) : Uniformity Of Diameter, Thickness And Hardness

OBJECTIVE

To determine the uniformity of diameter, thickness and hardness for the tablets.

INTRODUCTION

                                                          

       There are many types of tablets and capsules available in the market. They produce a unit dose and mainly for oral use. In order to prevent toxicity due to overdose of certain medication, tablets and capsules are subjected to pharmacopoeia standards which deal with the “added substances”. Those standards such as uniformity of content, uniformity of mass, uniformity of diameter, content of active ingredients, disintegration and dissolution can be found in the British Pharmacopoeia and United State Pharmacopoeia. Moreover, non-pharmacopoeial standards are also used to control the quality of procedures which include the thickness, hardness and friability of the tablets.

         Thus, it is important for the tablets and capsules to undergo quality test to make sure all tablets and capsules in the same type are uniform in physiochemical properties (such as diameter, thickness and hardness) to provide the same pharmacological effects and to prevent incorrect dose given to the patients.

METHOD

Apparatus and material

10 tablets of Non-Steroidal Anti-Inflammatory Analgesic which each tablets contain 500mg of Mefenamic acid B.P., Tablet Hardness Tester (PHARMATEST 2FNFE70551)

Procedures

1.      10 tablets of Non-Steroidal Anti-Inflammatory Analgesic were selected and were tested for diameter, thickness, and hardness using the Tablet Hardness Tester (PHARMATEST 2FNFE70551).

2.   The values of each tablet on their diameter, thickness and hardness are recorded.

3.      The deviation of tablets’ diameter, thickness and hardness are calculated. The deviation of individual unit from the mean diameter should not exceed ± 5% for tablets with diameter of less than 12.5 and ± 3% for diameter of 12.5 mm or more.

RESULTS

Tablet	Thickness (mm)	Diameter (mm)	Hardness (Newton)	Deviation of diameter (%)
1	6.69	16.87	110.5	+0.11
2	6.55	16.84	161.0	-0.07
3	6.63	16.84	147.3	-0.07
4	6.70	16.86	132.1	+0.05
5	6.58	16.86	162.8	+0.05
6	6.67	16.84	119.1	-0.07
7	6.65	16.84	139.7	-0.07
8	6.61	16.85	133.5	-0.01
9	6.66	16.86	128.0	+0.05
10	6.67	16.85	130.1	-0.01
Mean	6.641	16.851	136.41

DISCUSSIONS

      In this experiment, uniformity of diameter, thickness and hardness of the tablets available in the market are determined and tested by using 10 tablets of Non-Steroidal Anti-Inflammatory Analgesic. Each tablets contain 500mg of Mefenamic acid B.P. 

      According to the pharmacopoeia standard, each tablet with diameter more than 12.5mm, the deviation should not exceed ±3%. Next, for tablet with diameter less than 12.5mm, the deviation should not exceed ±5%.

        Based on the table above, the diameter of all the tablet are more than 12.50mm and the deviation of each tablets does not exceed deviation of  ± 3% according to the calculation. Therefore, it is proven that the diameter of tablet is uniform and comply with the pharmacopoeia standard.

The deviation of each tablet was calculated using the equation as shown below:  

       Positive value of deviation of diameter will be obtained if the diameter of tablet is bigger than the mean diameter, whereas for diameter of tablet that are less than the mean diameter, negative value of deviation of diameter will be obtained. However, errors may occur if the deviation of diameter is out of the required range which is more or less than 3% in this experiment with tablet diameter more than 12.50mm. These errors might be due to the irregular movement of lower punch or uneven feeding of granules into die during tableting process.

         From the data obtained, it shows that the average thickness, the average diameter and the average hardness of the 10 tablet selected are 6.641mm, 16.851mm and 136.41N respectively. The non-pharmacopoeia standards that are widely used by manufacturers are the thickness and hardness test. Tablet thickness is important in quality control test for tablet packaging. The thickness of tablet can affect the amount of active ingredient in the tablet and thus affect the therapeutic effectiveness of tablets. Moreover, it can also affect the packaging of the tablet as thick tablet is more difficult to fill in either blister or plastic container. Therefore, it is important to assure that tablets will fit into the container and can be accurately counted by the filling equipment.

CONCLUSION

From the experiment, all the 10 tablets of Non-Steroidal Anti-Inflammatory Analgesic which each tablets contain 500mg of Mefenamic acid B.P. have uniformity of diameter, thickness and hardness. All the tablet comply with the standard as the deviation of each tablet does not exceed ± 3% for the diameter of all the tablet more than 12.50mm according to the calculation.