Pharma gyan Pandit

 Disintegration test (U.S.P.)

Disintegration test is an official test. It is the time required for the tablet to break into particles, the disintegration test is a measure only of the time required under a given set of conditions for a group of tablets to disintegrate into particles.It is performed to identify the disintegration of tablet in particular time period. Disintegration test is not performed for controlled & sustained release tablets.

The U.S.P. device to test disintegration uses 6 glass tubes that are 3” long; open at the top and 10 mesh screen at the bottom end. To test for disintegration time, one tablet is placed in each tube and the basket rack is positioned in a 1-L beaker of water, simulated 

gastric fluid or simulated intestinal fluid at 37 ± 2⁰C such that the tablet remain 2.5 cm below the surface of liquid on their upward movement and not closer than 2.5 cm from the bottom of the beaker in their downward movement. 

Move the basket containing the tablets up and down through a distance of 5-6 cm at a frequency of 28 to 32 cycles per minute. Floating of the tablets can be prevented by placing perforated plastic discs on each tablet.

According to the test the tablet must disintegrate and all particles must pass through the 10 mesh screen in the time specified. If any residue remains, it must have a soft mass.

Liquids used in disintegration

a)     Water

b)     Simulated gastric fluid (pH = 1.2 HCl),

c)       Simulated intestinal fluid (pH = 7.5, KH₂PO₄ (phosphate buffer) + pancreatic enzyme + NaOH)

Disintegration testing conditions and interpretation

S.	Type of tablets	Medium	Temp.	limit
1	Compressed uncoated		37 ± 2 0C	15 minutes or as per individual monograph
2	Sugar coated If 1 or 2 tablets fail	Water 0.1 N HCL	37 ± 2 0C	60 minutes or as per individual monograph
3	Film coated	water	37 ± 2 0C	30 minutes or as per individual monograph
4	Enteric coated	0.1 N HCL & Phosphate buffer pH 6.8	37 ± 2 0C	1 hr or as per individual monograph
5	Dispersible/ Effervescent	water	37 ± 2 0C	LST < 3 minutes or as per individual monograph
6	Buccal tablets		37 ± 2 0C	4 hr or as per individual monograph

U.S.P. method for uncoated tablets:

Start the disintegration test on 6 tablets. If one or two tablets from the 6 tablets fail disintegrate completely within 30min repeat the same test on another 12 tablet. (i.e. the whole test will consume 18 tablets). Not less than 16 tablets disintegrate completely within the time. If more than two tablets (from the 18) fail to disintegrate, the batch must be rejected.

For Coated tablets:

To remove or dissolve the coat, immerse the tablet in distilled water for 5min. Put the tablet in the apparatus in water or HCL for 30 min at 37^oC (according to the U.S.P). If not disintegrated, put in intestinal fluid. If one or two tablets fail to disintegrate, repeat on 12 tablets. So 16 tablets from the 18 must completely disintegrate within the time, if two or more not disintegrated the batch is rejected.

U.S.P. and B.P Method for Enteric coated tablets:

1. Put in distilled water for five minutes to dissolve the coat.

2. Then put in simulated gastric fluid (0.1M HCL) for one hour.

3. Then put in simulated intestinal fluid for two hours.

If one or two tablets fail to disintegrate, repeat this test on another 12 tablets. So 16 tablets from 18 should completely disintegrate. If more than two fail to disintegrate the patch must be rejected.