This test is to determine whether Aspirin/Paracetamol tablets disintegrate within a prescribed time in a liquid medium (see B.P Appendix XII).
Apparatus: The Copley disintegration tester consists of 4 rigid basket rack assemblies each supporting six cylinder transparent tubes. A tablet is placed into each tube and a cylindrical transparent plastic disc placed on top of each. Each disc has 5 holes and 4 triangular shaped groves. It is important that the discs are placed such that the triangles points downwards.
Each assembly is suspended in a 1000 mL beaker held in a water bath heated and maintained at 37oC. The volume of liquid in each beaker is such that when the assembly is in the highest position the wire mesh is at least 15mm below the surface of the liquid and when in the lowest position the wire mesh should be at least 25mm above the bottom of the beaker. The open ends of the tubes must remain above the surface of the liquid. This volume corresponds to 800 mL.
The disintegration test was setup according to its operational manual. The temperature of the disintegration medium will be ensured at 37oC.
Three different categories of Aspirin tablets used in this experiments are
- Aspirin 75 mg Enteric coated (EC or gastro-resistant)
- Aspirin 75 mg dispersible tablets (DT)
- Aspirin 300 mg tablets (FC)
Six tablets of each category are taken in random and placed individually in a tube followed by a plastic disc.
Select TEST from the main menu and use the key pad to enter the required duration (120 min) and press start to initiate these test.
The tubes are raised and lowered 28-32 times a minutes in a liquid medium. The test duration will depend on the tablet type explained below.
The test is passed if
- No residue remains
- Any remaining residue consists of a soft mass having no palpably firm un- moistened core.
- Only fragments of coating (tablets) or any fragments of shell (capsules) remain.
Table 1. Disintegration test parameters
|Coated (film)||< 30 min||Water|
|Other coated tablets||<60 min||Water, If no disintegration occurs repeat the test on a further 6 tablets, replacing water by 0.1M HCl|
|Enteric coating||>120 min||0.1M HCl,|
|<60 min||pH 6.8 phosphate buffer|
|Effervescent||< 5min||200 mL water at 20oC|
|Soluble||< 3 min||Water at 20oC|
|Dispersible||< 3 min||Place 2 tablets in 100 mL water at 20 oC stir
until completely dispersed. A smooth dispersion is produced which passes through a sieve screen 22 (710uM).
Note your observations in the following table
Table 2: Disintegration test results for different categories of Aspirin tablets
|Aspirin 75 mg
EC tablets in
pH 6.8 buffer
75 mg EC
0.1 M HCl
75 mg DT
tablets in water
Discuss the results based on the disintegration times (table 2) of the 3 different categories of Aspirin tablets.