DISINTEGRATION TEST FOR TABLETS AND CAPSULES
DISINTEGRATION TEST:- This test is provided to determine whether tablets or capsules disintegrate within the prescribed time when placed in a liquid medium under the experimental conditions stated below.
APPARATUS:- The apparatus consists of a basket-rack assembly, a 1000 mL, low-form beaker, 138–160 mm in height and having an inside diameter of 97–115 mm for the immersion fluid, a thermostatic arrangement for heating the fluid between 35 °C and 39 °C and a device for raising and lowering the basket in the immersion fluid at a constant frequency rate between 29 and 32 cycles per minute, through a distance of not less than 53 mm and not more than 57 mm. The volume of the fluid in the vessel is such that at the highest point of the upward stroke the wire mesh remains at least 15 mm below the surface of the fluid and descends to not less than 25 mm from the bottom of the vessel on the downward stroke. At no time should the top of the basket- rack assembly become submerged. The time required for the upward stroke is equal to the time required for the downward stroke and the change in stroke direction is a smooth transition rather than an abrupt reversal of motion. The basket-rack assembly moves vertically along its axis.
BASKET-RACK ASSEMBLY: – The basket-rack assembly consists of six open-ended transparent tubes each 75.0–80.0 mm long and having an internal diameter of 20.70–23.00 mm and a wall 1.0–2.8 mm thick; the tubes are held in a vertical position by two plates, each 88–92 mm in diameter and 5.00–8.50 mm in thickness, with six holes, each 22–26 mm in diameter, equidistant from the centre of the plate and equally spaced from one another. Attached to the lower surface of the lower plate is a woven stainless steel wire mesh which has a plain square weave with 1.8–2.2 mm apertures and with a wire diameter of 0.570–0.660 mm. The parts of the apparatus are assembled and rigidly held by means of three bolts passing through the two plates. A suitable means is provided to suspend the basket-rack assembly from the raising and lowering device using a point on its axis.
DISCS:- The use of discs is permitted only where specified or allowed. Each tube is provided with a cylindrical disc 9.35–9.65 mm thick and 20.55–20.85 mm in diameter. The disc is made of a suitable, transparent plastic material having a specific gravity of 1.18–1.20. Five parallel 1.9–2.1 mm holes extend between the ends of the cylinder. One of the holes is centred on the cylindrical axis. The other holes are centred 5.8–6.2 mm from the axis on imaginary lines perpendicular to the axis and parallel to each other. Four identical trapezoidal-shaped planes are cut into the wall of the cylinder nearly perpendicular to the ends of the cylinder. The trapezoidal shape is symmetrical; its parallel sides coincide with the ends of the cylinder and are parallel to an imaginary line connecting the centres of two adjacent holes 6 mm from the cylindrical axis. The parallel side of the trapezoid on the bottom of the cylinder has a length of 1.5–1.7 mm and its bottom edges lie at a depth of 1.50–1.80 mm from the cylinder’s circumference. The parallel side of the trapezoid on the top of the cylinder has a length of 9.2–9.6 mm and its centre lies at a depth of 2.5–2.7 mm from the cylinder’s circumference. All surfaces of the disc are smooth. If the use of discs is specified add a disc to each tube and operate the apparatus as directed under procedure.
PROCEDURE:- Place one dosage unit in each of the six tubes of the basket and if specified add a disc. Operate the apparatus using water as the immersion fluid unless another liquid is specified and maintain its temperature at 35–39 °C. At the end of the specified time lift the basket from the fluid and observe the dosage units, all of the dosage units have disintegrated completely. If one or two dosage units fail to disintegrate repeat the test on 12 additional dosage units. The requirements of the test are met if not less than 16 of the 18 dosage units tested are disintegrated.
This apparatus is used for tablets and capsules having size not greater than 18 mm
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