INTRODUCTION
Oral dosage forms such as tablets and capsules have to
follow the pharmacopoeial standards which involve “added substances” that may
influence their toxicity, interference with analytical method and so on. The
procedures to assess the quality or standard of tablets and capsules are
important to ensure that a tablet or capsule exerts its full pharmacological
actions and also to determine the uniformity of the physical properties. The
standards that are found in the British Pharmacopoeia includes the uniformity
of diameter, uniformity of weight, content of active ingredient, uniformity of
content, disintegration and dissolution. The uniformity of diameter and weight
may increase the patient compliance due to their uniform size of appearance.
The uniformity of active ingredient and content will make sure the dosage
supplied to the patients is correct and preventing from overdose cases and so
on. Uniformity in disintegration and dissolution will make sure that each
tablet and capsule will have similar reaction when metabolized in the body.
There are also non-pharmacopoeial standards that are not included in the
British Pharmacopoeia, but still influence the properties of the tablets and
capsules. The non-pharmacopoeial standards involve hardness, friability and
bioavailability of the tablets and capsules. But now, hardness and friability standards
also considered as pharmacopoeial standards and can be found in pharmacopoeia. All
the experiments below that will be conducted will show the application of a
number of selected physical and dosage performance tests on the samples of
commercially available tablets and capsules.
EXPERIMENT 1: UNIFORMITY OF DIAMETER, THICKNESS AND HARDNESS
Apparatus and materials:
Tablet Testing
Instrument (PHARMATEST PTB 311), weighing boat, 10 tablets
Procedures:
1. 10 tablets were
selected and the tests for uniformity of diameter, thickness, and hardness were
carried out using the Tablet Testing Instrument (PHARMATEST PTB 311).
2. The deviation of
individual unit from the mean diameter was calculated and the value should not
exceed ± 5% for tablets with diameter of less than 12.5mm and ± 3% for diameter
of 12.5mm or more.
Results:
|
Bil
|
Thickness (mm)
|
Diameter (mm)
|
Percentage deviation of diameter (%)
|
Hardness (N)
|
|
1
|
5.50
|
12.85
|
+0.16
|
134.20
|
|
2
|
5.50
|
12.83
|
0.00
|
134.90
|
|
3
|
5.50
|
12.84
|
+0.08
|
134.20
|
|
4
|
5.59
|
12.82
|
-0.08
|
133.65
|
|
5
|
5.51
|
12.80
|
-0.23
|
148.93
|
|
6
|
5.48
|
12.83
|
0.00
|
159.59
|
|
7
|
5.60
|
12.84
|
+0.08
|
150.17
|
|
8
|
5.56
|
12.83
|
0.00
|
158.17
|
|
9
|
5.47
|
12.80
|
-0.23
|
150.00
|
|
10
|
5.50
|
12.82
|
-0.08
|
143.80
|
|
Average
|
5.52
|
12.83
|
|
144.76
|
The deviation of
diameter for individual unit can be obtained by using the formula:
Percentage
deviation = 
Discussion:
This experiment is conducted to determine the
diameter, thickness and hardness of the tablets. From the result, we find that the
thickness showed uniformity where it lies between 5.47 mm to 5.60 mm and the
mean is 5.52 mm. Tablet thickness is an important quality control test for
tablet packaging. This is to ensure that tablets can fit into the container and
they can be accurately counted by the filling equipment. Some filling
equipments depends on the uniformity of thickness as its counting mechanism. Tablet
thickness can vary without any change in its weight. This may depends on the
die of the tablet and the force used to compress the powder. It also can be
influenced by the difference density of granules and the speed of tablet compression.
Besides, from the results, the diameter obtained for all the ten tablets have
such similar values and the average of the diameter of the tablets is 12.83 mm.
We know that if the diameter of tablets is 12.5 mm or more, thus the deviation
should be ± 3%. If the diameter of tablets is less than 12.5 mm, thus the
deviation should be ± 5%. From the results, we find that all the diameters of
the tablets are more than 12.5 mm and the deviations for all individual tablets
are less than ± 3%. This means that the tablets generally have uniform
diameter. The uniform size or diameter of tablets may help to increase the
patient compliance and avoid them from being confuse with different size of the
tablets. The slight variations in diameter of the tablets may due to uneven
surface of punch or less accurate measurement with the Tablet Testing
Instrument. In addition, tablets should exert the adequate crushing strength,
or hardness, to withstand mechanical shock during handling in production,
packaging, distribution and storage. In the practical, the testing instrument
measures the force required to break the tablets. The hardness showed
uniformity as it lies between 133.65 N to 159.59 N. The hardness of tablets
depends on the weight of the material used, amount of binder
(more binder, more hardness), method of granulation in preparing the tablet and compressive force. The hardness of tablet is important as it affects
the disintegration and dissolution factors. Thus, we must design tablets that
have medium level of hardness to ensure that it can easily dissolve and not
easily break.
Conclusion:
The thickness,
diameter and hardness of the tablets are in uniform as they lie between a
certain range and within the fixed percentage deviation. The uniformity of the diameter is important in order to
design drugs with similar size and may increase patient compliance. The
uniformity of thickness of the tablets is important for packaging process. The
hardness of the tablets is important to ensure the drugs or tablets have
effective hardness that will influence disintegration and dissolution.
Question and answer:
1. What are the
objectives of the tests for uniformity of diameter and uniformity of content?
The test for uniformity of diameter is conducted to determine the quality
of the sizes and appearances of the tablets in order to increase patient
compliance. The purpose of test for uniformity of content is to determine the uniformity of active ingredients in
the tablet and ensure the dosage supplied to the patients is correct.
2. State the types of
tablets and capsules that must be tested for the uniformity of diameter and
uniformity of content.
The uniformity of diameter is tested for all uncoated and coated tablets
except enteric tablets, film-coated tablets and sugar-coated tablets. For uniformity
of content, it involves uncoated and coated tablets and also hard and soft
capsules.
References:
No comments:
Post a Comment