Disintegration test apparatus is widely used in pharmaceuticals to identify the disintegration properties of various types of tablets and capsules. The DT apparatus decides whether or not tablets or capsules disintegrate within a recommended time once placed in a liquid medium.
What are Disintegration and Principle:
Disintegration is defined as that state in which no residue of the tablet and capsule remains on the screen of the apparatus or, if a residue remains, it may be consists of a fragment of insoluble coating of the tablet or capsule shells or is a soft mass with no palpable core.
If Discs have been used with capsules, any residue remaining on the lower surface of discs only consists of fragments of their shells.
Disintegration Test apparatus assembly:
DT apparatus assembly Consists of the following parts:
- Rigid Baskets
- Cylindrical Disks
1. Rigid Baskets:
Rack assembly supports six cylindrical glass tubes, 77.5 ± 2.5 mm long, 21.5 mm in internal diameter, and a wall thickness of about 2 mm.
The tube is held vertically by two superimposed, transparent plastic plates, 90 mm in diameter and 6 mm thick, perforated by six holes having the same diameters as tubes.
The hole is equidistant from the center of the plate and is equally spaced from one another, that is attached to the lower side of the lower plate is a piece of woven gauze made from stainless steel wire (10 mesh screen size). These are 635 mm in diameter and have a nominal mesh aperture of 2.00 mm.
The upper plate is secured with a tempered stainless steel circle punctured by six gaps, each around 22 mm in breadth, accommodating our cylinders and holding them between the plastic plates. The hole coincides with those of the upper plastic plate and the upper open ends of glass tubes.
Plates are held inflexibly in position and 77.5 mm separated by vertical metal rods on the outskirts. The upper plate center is fixed to the metal rod enabling the assembly to be attached to a mechanical device capable of raising and lowering it quickly at a constant frequency of between 29 and 32 cycles/minute through a distance of 50 to 60 mm.
The design of the basket-rack assembly may be somewhat different provided specifications for the glass tubes, and the screen mesh sizes are unchanged.
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4. Cylindrical Disks:
The dimensions of each hole inside disk are 20.7 ± 0.15 mm and 9.5 ± 0.15 mm thick and made of transparent plastic with a density of 1.18 to 1.20, and pierced with five holes, each of 2 mm in diameter, one at center and another four spaced equally on a circle of radius 6 mm from the center of the disc and Four similarly divided groove is cut in the horizontal surface of the circle so that at the upper surface of the plate, they are 9.5 mm wide and 2.55 mm deep, and at the lower surface 1.6 mm square.
Assembly is suspended in the liquid medium in a suitable vessel, preferably in a 1000 ml beaker. The height of the wire mesh is a minimum of 25 millimeters below the liquid surface, and at its lower purpose is a minimum of 25 millimeters on top of the beaker.
A Thermostat is an Arrangement for heating the liquid and maintaining the temperature around 37 ± 2° C.
Disintegration Test Method:
Unless otherwise explicit within the individual monograph, introduce one tablet or capsule into every glass tube or six tablets. If directed within the acceptable general monograph, add a disc to every tube.
Suspend the assembly within the beaker containing the desired liquid, operate the equipment for the desired time, and take away the assembly from the liquid. The tablets and capsules pass the test if all of them have completely disintegrated.
If one or two tablets/capsules fail to disintegrate, repeat the test on 12 additional tablets/capsules; not less than 16, of a total of 18 tablets/capsules, tested for disintegration.
If the tablets or capsules adhere to the disc and the examined preparation fails to comply, repeat the test omitting the disc. The preparation complies with the test if all the tablets or capsules disintegrate in a repeat test.
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Different types of tablets Disintegration times
|Tablets Types||Disintegration Time|
|Uncoated tablets||15 min (BP, IP), 30 min (USP)|
|Film-coated||30 min (BP), others coated tablets 60 min|
|Sugar-coated||60 min (BP)|
|Effervescent tablets||<5 min (BP, IP)|
|Dispersible tablets||<3 min (BP, IP)|
|Enteric-coated tablets||With 0.1N Hcl- No disintegration in 120 min|
With 6.8 pH phosphate buffer in 60 min
|Hard gelatin Capsules||30 min as per BP, and USP|
|Soft gelatin Capsules||30 min as per BP|
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State at which no residues remain of tablets on-screen of apparatus, besides fragments of coated tablets.
55 mm ± 2 strokes/minute.
Disintegration time is the time required to break the unit dosages into small granules under specified conditions.
The disk is used to Allow the tablets to stay deep in the water during the entire process.
- Pharmacopeia general chapters <701> Disintegration