PRACTICAL 3: ASSESSMENT OF QUALITY OF TABLETS AND CAPSULE (1)

INTRODUCTION

            Quality control is an essential operation of the pharmaceutical industry. A drug must be proven safe and therapeutically active before marketed. The performance of the drug formulation is tested during the assessment of drugs to ensure its consistency. Like all the other dosage forms, tablets and capsules are subjected to those pharmacopoeia standards which deal with “added substances” with respect to their toxicity, interference with analytical methods, etc. There are several procedures which apply specifically to tablets and capsules to examine the quality of the formulation. These procedures not only ensure the effectiveness of the pharmacological actions, but also to determine the uniformity of the physical properties of the official tablet/capsule, irrespective of the manufacturer. 

            The testing specifications established for tablets include physical, chemical and biological tests. Physical testing specifications can comprise of size, shape, colour, friability, breaking force or hardness, and disintegration. Inspecting the appearance of a tablet can be a quick quality check. Such standards are found in the British Pharmacopoeia and United Pharmacopoeia which are uniformity of diameter, uniformity of weight, content of active ingredient, uniformity of content, friability, disintegration and dissolution. Besides, there are some quality control procedures which are widely used but not defined by the pharmacopoeias such as thickness and hardness.

Experiment 1: Physical Appearance

1.      A type of tablet or capsule is selected from the provided samples. The shape, colour, diameter, thickness and other physical characteristics are examined and noted. 

Characteristics	Tablet	Capsule
Shape	Round	Cylindrical with hemispherical ends
Colour	Pink	Yellow & blue
Diameter	1.8cm	0.7cm
Thickness	0.5cm	0.7cm
Coating	Yes	-
Wording	APP 250	MEFA

DISCUSSION:

            Size and shape of tablets and capsules may directly affect a patient’s ability to swallow a particular drug product. These factors also affect the transit of the product through the pharynx and esophagus. Larger tablets and capsules will be difficult to pass through the esophagus thus have a prolonged esophageal transit time. This can lead to disintegration of the product in the esophagus and/or cause injury to the esophagus, resulting in pain and localized esophagitis and the potential for serious sequelae. Other adverse events such as pain, choking, and aspiration are related to swallowing difficulties. These undesired effects increasingly occur at larger tablet and capsule sizes. 

            In vitro studies suggest that flat tablets have greater adherence to the esophagus than capsule-shaped tablets. Studies in humans have also suggested that oval tablets may be easier to swallow and have faster oesophageal transit times than round tablets of the same weight. Patient compliance with medication regimens may be influenced by the size and shape of a tablet or capsule.

            The presence and composition of a coating can also potentially affect the ease of swallowing tablets or capsules. The lack of a film coating can decrease or prevent tablet mobility compared with a coated tablet of the same size and shape. Coating also can affect other factors that contribute to patient acceptance, such as palatability and smell. The wording printed on the tablets or capsules is primarily for recognition purpose.

PRACTICAL 3: ASSESSMENT OF QUALITY OF TABLETS AND CAPSULES (2)

EXPERIMENT 2: Uniformity Of Diameter, Thickness And Hardness

OBJECTIVES:

1.      To measure the uniformity of diameter and thickness of tablets

2.      To analyse the hardness of tablets

MATERIAL:

10 tablets, Tablet Testing Instrument (PHARMATEST PTB 311), ruler

PROCEDURE

1.      10 tablets are selected and carried out to test the uniformity of diameter, thickness and hardness by using the Tablet Testing Instrument (PHARMATEST PTB 311).

2.      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 12.5mm or more.

Tablet	Diameter (DI) / mm	Thickness (TH) / mm	Hardness (H) / N
1	12.840	5.590	138.19
2	12.830	5.610	110.66
3	12.820	5.580	125.44
4	12.800	5.530	121.01
5	12.810	5.580	150.01
6	12.810	5.580	105.68
7	12.790	5.440	112.51
8	12.820	5.570	137.82
9	12.810	5.640	138.01
10	12.800	5.530	121.01

Tablet	Exact diameter (mm)	Average diameter (mm)	Difference in diameter (mm)
1	12.840	12.813	0.027
2	12.830	12.813	0.017
3	12.820	12.813	0.007
4	12.800	12.813	- 0.013
5	12.810	12.813	- 0.003
6	12.810	12.813	- 0.003
7	12.790	12.813	-0.023
8	12.820	12.813	0.007
9	12.810	12.813	- 0.003
10	12.800	12.813	- 0.013

Calculation for percentage of deviation

DISCUSSION:

From the experiment above, we found that the ten tablets tested have very high uniformity of diameter, thickness and also hardness.

            All of the ten tablets tested are having diameter more than 12.5 mm, which their diameters range from 12.79 mm to 12.84 mm. The mean diameter obtained by summation of the measured diameters divided by the total number of unit tested is 12.813 ≈ 12.81 mm.

            Taking the largest diameter measured, which in this case is 12.84mm, the deviation obtained is 0.211%. Meanwhile, the deviation obtained using the smallest diameter measured which is 12.79 mm is - 0.179%. Both the deviations are within the range of 3% deviation, showing that these ten tablets measured are having quite a high uniformity of diameter.

            Using the Tablet Testing Instrument (PHARMA TEST PTB 311), the thickness and the hardness of the tablets are also obtained. The thickness measured range from 5.53 mm t0 5.64 mm and the mean thickness obtained is 5.565 mm.

            Diameter, thickness and density are the three basic components that may influence the weight of one tablet. Density of the tablet increases when the compression force for the active ingredient and the recipient increases, causing the hardness of the tablet increases as well. If the tablet is too hard, it may not be able to disintegrate in the required period of time and take longer time to dissolute; meanwhile, if the tablet is too soft, it will be more difficult to be handled in subsequent processes such as shipping and packaging as it breaks easily. Theoretically, the diameter of the tablet and its density of the powder blend should remain unchanged. Thus, by monitoring the thickness of the tablet, some potential problems regarding to the tablet’s weight and the uniformity of the tablet content can be detected at the early stage.

PRACTICAL 3 : ASSESSMENT OF QUALITY OF TABLETS AND CAPSULES (3)

EXPERIMENT 3: TABLET FRIABILITY

OBJECTIVES

1.      To determine the percentage loss of weight of certain amount of tablets.

2.      To determine the physical strength of tablets upon exposure to mechanical shock or attrition.

INTRODUCTION

       Friability is defined as the percentage of weight loss by tablets due to mechanical action or friction during the test. The initial weights of certain amount of tablets are measured as a whole. Friability refer to the ability of the compressed tablets to avoid fracture and breaking during the transport. It is related to tablet harness and designed to evaluate the ability of tablet to withstand aberration in packing, handling and shipping. It is measured by the use of friability tester.

APPARATUS AND MATERIAL

10 tablets

2 Weighting boats

PROCEDURES:

Process of friablity of tablets

1.      10 tablets were selected and weighted.

2.      All tablets were put into the drums of tablet aberration and friability tester. The rate of rotation was set at 100 rpm for 10 minutes and the operation started.

3.      All the tablets were removed and ensure freedom from dust or powder at the end of operation. The tablets were reweighted. The percentage loss of weight determined.

4.      Compressed tablet should not lose more than 1% of its weight.

RESULT:

	WEIGHT OF 10 TABLETS
Before	5.7752
After	5.7215
Differences	0.0537

DISCUSSION:

       A maximum weight loss should not be more than 1% of the weight of the tablets during friability test. Generally, it is acceptable and any broken or smashed tablets were not picked up. Thus, after calculation we got 0.9298% which is the acceptable one. There are several factors affected if the percentage loss is greater than 1%. Firstly, the tablet may be expired so, the hardness is too low causing it to fracture than normal. Then, there are several changes to the rpm of the machine which is 75rpm. In the lab, the are 2 machine that has 2 different rpm which is 25rpm and 75 rpm. 

CONCLUSION:

     For the conclusion, the percentage of lost that we got is 0.9298% (below than 1%) , which show that the tablets promotes a good behaviour.

PRACTICAL 3 : ASSESSMENT OF QUALITY OF CAPSULES AND TABLETS (4)

EXPERIMENT 4: UNIFORMITY OF WEIGHT OF TABLETS AND CAPSULES.

OBJECTIVE:

 To determine the uniformity of weight of tablets and capsules

MATERIAL/APPARATUS:

20 tablets, 20 capsules, weighing boat, weighing balance.

PROCEDURE:

Tablets

1.      20 tablets selected at random are weighed. The average weight is determined.

2.      Tablets are individually weighed and for each tablet, the percentage deviation of its weight from the average weight is determined. 

3.      The deviation of individual weight from the average weight should not exceed the limits given below. 

Average weight of tablet	Deviation (%)	Number of tablets
Less than 80 mg.	± 10.0	Minimum 18
	± 20.0	Maximum 2
80 mg to 250 mg	± 7.5	Minimum 18
	± 15.0	Maximum 2
More than 250 mg.	± 5.0	Minimum 18
	± 10.0	Maximum 2

Capsules

1.      20 capsules are selected at random. 

2.      One capsule is weighed. Capsule is opened and the contents are removed as completely as possible. The emptied shells are also weighed. The net weight of its content is weighed, that is by subtracting the weight of the shells from the weight of the intact capsule. 

3.      The procedure is repeated with other 19 capsules. 

4.      The average net weight from the sum of the individual net weights is weighed. 

5.      The percentage deviation is determined from the average net weight for each capsule. The deviation of individual net weight should not exceed the limits given below: 

Average net weight of capsule	Deviation (%)	Number of tablets
Less than 300 mg.	± 10.0	Minimum 18
	± 20.0	Maximum 2
300 mg or more	± 7.5	Minimum 18
	± 15.0	Maximum 2

RESULTS

Total weight of 20 tablets: 13.4523 g

Average of net weight = 13.4523 g

                                             20

                                    = 0.6726 g

X 100 %

Percentage deviation =   (weight of individual tablet – average weight ) 

                                                                    Average weight

                                     

Tablets

Tablet	Individual weight (g)	Percentage deviation (%)
1	0.6727	0.01
2	0.6791	0.97
3	0.6738	0.18
4	0.6514	-3.15
5	0.6740	0.21
6	0.6776	0.74
7	0.6605	-1.80
8	0.6506	-3.27
9	0.6731	0.07
10	0.6633	-1.38
11	0.6943	0.03
12	0.6719	-0.10
13	0.6731	0.07
14	0.6724	-0.03
15	0.6805	1.17
16	0.6740	0.21
17	0.6686	-0.59
18	0.6723	-0.04
19	0.6851	1.86
20	0.6864	2.05

Capsules

Total net weight of 20 capsules: 7.8212 g

Average of net weight=  7.8212 g

                                             20

                                    = 0.3911 g

X 100 %

Percentage deviation =   (net weight of individual capsule – average net weight ) 

                                                                    Average net weight

Capsule	Weight of individual capsule (g)	Weight of empty shell (g)	Net weight of individual capsule (g)	Percentage deviation (%)
1	0.4696	0.0734	0.3962	1.30
2	0.4623	0.0760	0.3863	-1.23
3	0.4650	0.0765	0.3885	-0.66
4	0.4352	0.0437	0.3915	-0.10
5	0.4705	0.0750	0.3955	1.13
6	0.4575	0.0721	0.3954	1.10
7	0.4475	0.0725	0.3750	-4.12
8	0.4699	0.0752	0.3947	0.92
9	0.4684	0.0752	0.3932	0.54
10	0.4701	0.0756	0.3945	0.87
11	0.4678	0.0745	0.3922	0.28
12	0.4590	0.0762	0.3828	-2.12
13	0.4692	0.0734	0.3958	1.20
14	0.4761	0.0774	0.3987	1.94
15	0.4774	0.0742	0.4032	3.09
16	0.4655	0.0796	0.3859	-1.33
17	0.4625	0.0764	0.3861	-1.28
18	0.4557	0.0745	0.3812	-2.53
19	0.4681	0.0763	0.3918	0.18
20	0.4725	0.0798	0.3927	0.41

DISCUSSION

Based on the results obtained, the average weight of tablet is 0.6726 g / 672.6 mg which is more than 250 mg. Hence the percentage deviations should have a minimum of 18 tablets within the range of ± 5.0 and maximum of 2 tablets within the range of 10.0. From the data obtained, it shows that the percentage deviations of all 20 capsules are between the range of ± 5.0 with the highest value of -3.27 %(capsule 8). This indicates that the tablets have a uniform and consistent weight. 

The average net weight of capsules is 0.3911 g/ 391.1 mg which is more than 300 mg. Thus, the percentage deviation should have a minimum of 18 capsules and maximum of 2 capsules in the range of ± 7.5 and ± 15.0 respectively. From the data obtained, no capsule reached ± 15.0 of standard deviation as the highest value is 3.09 %(capsule 15). The percentage deviation of all capsules lies between the ranges of ± 7.5 which indicates that the capsules have a uniform and consistent weight. 

There are some possible errors that might occur while conducting the experiment which may affect the accuracy of the readings. Some of it is vibration of table or in the floor and air current can cause fluctuations in the weighing balance. There might also some solids or dust on the weighing balance that is not removed before weighing procedure continued. The content of the capsules also might not completely remove thus decrease the accuracy of readings. 

CONCLUSION

Uniformity test of tablets and capsules weight and content is important to ensure the consistency of dosage units of each tablet and capsule. In this experiment, both preparations comply with the test as all percentage deviation is between the range that is determined in the British Pharmacopoeia.