GB1569613A - Disodium cromoglycate in a form - Google Patents

Description

(54) DISODIUM CROMOGLYCATE IN A NOVEL FORM (71) We, FISONS LIMITED, a British Company, of Fison House, 9 Grosvenor Street, London W1X OATH, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a new form of disodium cromoglycate.

In our British Patent No 1,122,284 we have described and claimed an insufflator device for use in the administration of powdered medicaments by inhalation looms prising a propellerAike device for carrying a power capsule rotatably mounted within a tubular housing by means of a shaft loosely journalled in a tapered bearing tube, the housing having a mouthpiece whereby a user can inhale air through the device. With that device, and other devices, e.g. that described in British Patent Specifi- cation No 1,331,2146, a user inhalers air through the device which causes a powder container mounted therein to rotate. Powder within the container is fluidised and dispensed into the air stream which is inhaled by the user. For optimum dispensing it has been found that the powdered medicament particles should be comparatively freeflowing but fine disodium cromodycate powders are not sufficiently free-flowing.

We have now found that this problem can be mitigated or overcome by forming powdered disodium cromoglycate into small soft granules. The formation of the disodium cromovlycate into soft granules also aids the filling of the disodium cromoglycate into capsules or other containers and can enable diluents such as coarse lactose, which have in the past been incorporated into powder inhalation compostions, to be omitted from the composition.

Accordingly the present invention provides particulate disoddum cromoglycate containing from 12 to 25%, and preferably from 17 to 23%, by weiplmt of water.

The disodium cromoglycate according to the invention may be made into soft granules described and claimed in our co-pending Application No 2606/76. (Serial No 1,569,611).

The ,disodium cromoglycate according to.

the invention may be made by adding water in the liquid phase to disodium cromoglycate containing insufficient water.

The disodium cromoglycate according to the invention may be converted to soft granules by subjecting it to controlled agglomeration. This controlled agglomeration may be carried out by, for example, extrud dng the particles of disodium cromoglycate through an aperture.

In this process finely 'divided disodium cromoglycate, e.g. having a mean particle size in the range 0.01 to 10 microns may be subjected to an initial treatment to cause the powder particles to be self-agglomerative. This treatment may be carried out by exposing the powder particles to water.

The powder particles may be mixed with an excess of liquid water, and the moistened material passed through an aperture, e.g.

a sieve such as la vibrating sieve, of approximately equal ;to or larger than the mesh size required in the final granules and then drying the resulting sieved material to the desired final solvent, e.g. water, content The material may then be idry granulated to give the required product.

The amount of water used in the granulation can, under certain circumstances, be critical. Thus we have found that use of greater than about 25% by weight of water may cause the granules to be too strong and dense.

The drying of the granules lis preferably effected in a preheated forced convection hot air oven. The temperature of drying is desirably from 60 to 1000c, and Imore ex- pecially from 80 to 900c.

The invention will now be illustrated by the following Example.

Example 1,000g of finely ground disodium cromoglycate of determined water content was placed in the bowl of a planetary mixer.

The calculated amount of water to bring the moisture content of the disodium cromoglycate to within the desired range was then added gradually, the sides of the mixer bowl being scraped regularly to ensure even moisture distribution. The damp disodium cromoglycate was then passed through a vibrating sieve having a mesh size of 1,000 microns. The product was then dried in a preheated forced convection hot air oven at 85 c for 2 hours until the moisture content of the granules was in the range 5 to 8% by weight. The granules were then sieved through a 250 micron screen. The resulting granules were found to flow well and could be filled easily into gelatin capsules.

WHAT WE CLAIM IS: 1. Particulate disodium cromoglycate containing from 12 to 25% by weight of water.

2. Disodium cromoglycate according to Claim 1 and containing from 17 to 23% by weight of water.

3. Diisodium cromoglycate according to Claim 1 or 2 and having a mean particle size in the range 0.01 to 10 microns.

4. Disodium cromoglycate according to Claim 1 and substantially as hereinbefore described in the Example.

Reference has been directed in pursuance of section 9, subsection (1) of the Patents Act 1949, to Patent No. 1242212.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. The calculated amount of water to bring the moisture content of the disodium cromoglycate to within the desired range was then added gradually, the sides of the mixer bowl being scraped regularly to ensure even moisture distribution. The damp disodium cromoglycate was then passed through a vibrating sieve having a mesh size of 1,000 microns. The product was then dried in a preheated forced convection hot air oven at 85 c for 2 hours until the moisture content of the granules was in the range 5 to 8% by weight. The granules were then sieved through a 250 micron screen. The resulting granules were found to flow well and could be filled easily into gelatin capsules. WHAT WE CLAIM IS:

1. Particulate disodium cromoglycate containing from 12 to 25% by weight of water.

2. Disodium cromoglycate according to Claim 1 and containing from 17 to 23% by weight of water.

3. Diisodium cromoglycate according to Claim 1 or 2 and having a mean particle size in the range 0.01 to 10 microns.

4. Disodium cromoglycate according to Claim 1 and substantially as hereinbefore described in the Example.

Reference has been directed in pursuance of section 9, subsection (1) of the Patents Act 1949, to Patent No. 1242212.