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4.22 DISINTEGRATION TEST FOR SUPPOSITORIES AND PESSARIES

      This test is provided to determine compliance with the limits on Disintegration stated in the individual monographs except where the label states that the suppositories or pessaries are intended for modified release or for prolonged local action. The test for disintegration of suppositories and pessaries determines whether suppositories and pessaries disintegrate or soften within a prescribed time when placed in an immersion fluid under the prescribed experimental conditions. 

Apparatus

(a) A transparent sleeve of glass or suitable plastic, of height 60 mm with an internal diameter of 52 mm and an appropriate wall thickness (Fig. 1).

          (b) A metal device consisting of two stainless metal discs, each of which contains 39 holes, each 4 mm in diameter, being distributed as indicated in Fig. 1. The diameter of the discs is closely similar to the internal diameter of the sleeve. The discs are separated by a distance of about 30 mm. The metal device is attached to the outer sleeve by means of three equally-spaced hooks.

      For vaginal tablets use with the hook-end downwards as indicated in Fig. 2.

Procedure

MOULDED SUPPOSITORIES Place a suppository on the lower perforated disc of the metal device and then insert the device into the cylinder and attach this to the sleeve. Repeat the operation with a further two suppositories and metal devices and sleeves. Unless otherwise stated in the individual monograph, place each piece of apparatus in a vessel containing at least 4 litres¹ of water at 36.5º±0.5º and fitted with a slow stirrer and a means of holding the top of the apparatus 90 mm below the surface of the water. After each 10 minutes invert each apparatus without removing it from the liquid.

      Disintegration is complete when the moulded suppository

      (a) is completely dissolved or

      (b) has dispersed into its component parts, which may collect on the surface (melted fatty substances), sink to the bottom (insoluble powders) or dissolve or

      (c) has become soft, which may involve an appreciable change in shape, without necessarily separating into its components, and the mass has no solid core offering resistance to pressure with a glass rod.

      Disintegration occurs in not more than 30 minutes for fat-based suppositories and in not more than 60 minutes for water-soluble suppositories, unless otherwise stated in the individual monograph.

RECTAL CAPSULES Carry out the procedure described under Moulded Suppositories. Disintegration is complete when the gelatin shell ruptures, allowing release of the contents.

      Disintegration occurs in not more than 30 minutes.

MOULDED PESSARIES Carry out the procedure and use the criteria for disintegration described under Moulded Suppositories.

¹All three pieces of apparatus may alternatively be placed together in a vessel containing at least 12 litres. 

      Disintegration occurs in not more than 1 hour unless otherwise stated in the individual monograph.

VAGINAL CAPSULES Carry out the procedure described under Moulded Suppositories and use the criterion for disintegration described under Rectal Capsules.

      Disintegration occurs in not more than 30 minutes.

VAGINAL TABLETS Place the apparatus in a vessel of suitable diameter containing water at 36.5º±0.5º. Adjust the level of the liquid by the gradual addition of water at 36.5º±0.5º until the perforations in the metal disc are just covered by a uniform layer of water. Place one vaginal tablet on the upper perforated disc and cover the apparatus with a glass plate to maintain appropriate conditions of humidity. Repeat the operation with a further two vaginal tablets.

      Disintegration is complete when

      (a) there is no residue on the perforated plate or

      (b) if a residue remains, it consists only of a soft or frothy mass having no solid core offering resistance to pressure with a glass rod.

      Disintegration occurs in not more than 30 minutes, unless otherwise stated in the individual monograph.