Disintegration

1. DISINTEGRATION

2. DISINTEGRATION TEST (USP):
For a drug to be readily available to the body,
it must be in solution.
For most tablets, the first important step
towards solution is breakdown of the tablet into
smaller particles or granules, a process called
disintegration.

3. Tablet disintegration is important for tablets containing medicinal agents (such as
antacids and antidiarrheals) that are not intended to be absorbed but rather to act
locally within the GI tract.
Tablet disintegration provides drug particles with an increased surface area for activity
within the GI tract.
Types of tablets Time of disintegration
Uncoated tablets 15 minutes
Sugar coated tablets 60 minutes
Film coated tablets 30 minutes
Nitroglycerine tablets 2 minutes
Buccal tablets 4 hours

4. Disintegration apparatus
All USP tablets must pass a test for disintegration, which is conducted invitro
using a testing apparatus.
 The apparatus consists of a basket and rack assembly containing six open-ended
transparent tubes of USP-specified dimensions, held vertically upon a 10-mesh
stainless steel wire screen.
 During testing, a tablet is placed in each of the six tubes of the basket, and through
the use of a mechanical device, the basket is raised and lowered in the immersion
fluid at 29 to 32 cycles per minute, the wire screen always below the level of the
fluid.
 For uncoated tablets, buccal tablets and sublingual tablets, water at about 37˚C
as the immersion fluid unless another fluid is specified in the individual monograph.

6. Disintegration test
We start with 6 tablets (each tablet in each tube), if one or more
failed to disintegrate completely, test should be repeated for additional 12 tablets,
not fewer than 16 of the total 18 tablets disintegrate completely.
Enteric coated tablets are similarly tested. Except that tablets are tested in
simulated gastric fluid for one hour, after which no sign of no disintegration,
or softening must be seen.
They are immersed in simulated intestinal fluid for the time specified in the
monograph, during which time the tablets disintegrate completely for the positive
test.