IE45262B1

IE45262B1 - Disodium cromoglycate in a novel from

Info

Publication number: IE45262B1
Application number: IE1844/80A
Authority: IE
Original assignee: Fisons Ltd
Priority date: 1976-01-23
Filing date: 1977-01-05
Publication date: 1982-07-28
Also published as: IE45262L; IE45261L; IE45261B1

Description

The present invention relates to a new form of disodium cromoglycate.

In Patent Specification No. 31503 we have described and claimed an insufflator device for use in the administration of powdered medicaments by inhalation comprising a propeller-like device for carrying a powder capsule rotatably mounted within a tubular housing by means of a shaft loosely journalled in a tapered bearing tube, the housing having a mouth10 piece whereby a user can inhale air through the device. With that device, and other devices, e.g. that described in British Patent Specification No. 1,331,216, a user inhales 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. Por optimum dispensing it has been found that the powdered medicament particles should be comparatively freeflowing but fine disodium cromoglycate 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 cromoglycate into soft granules also aids the filling of the disodium cromoglycate into capsules or other containers and can enable diluents such as 45363 coarse lactose, which have in the past been incorporated into powder inhalation compositions, to be omitted from the composition.

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

The disodium cromoglycate according to the invention may be made into soft granules described and claimed in Patent Specification No. 45260.

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 subject15 ing it to controlled agglomeration. This controlled agglomeration may be carried out by, for example, extruding the particles of disodium cromoglycate through an aperture.

In this process finely divided disodium cromo20 glycate, 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 selfagglomerative. 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 a 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 dry 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 - 4 water may cause the granules to be too strong and dense. a a a ο The drying of the granules is preferably effected in a preheated forced convection hot air oven. The temperature of drying is desirably from 60 to 100°C, and more expecially from 80 to 90°c.

The invention will now be illustrated by the following Example.

EXAMPLE l,000g of finely ground disodium cromoglycate Cf 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 reqularly 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°G 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.

Claims

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

2. Disodium cromoglycate according to Claim 1 5 and containing from 17 to 23% by weight of water.

3. Disodium cromoglycate according to Claira 1 or 2 and having a mean particle siae in the range 0.01 to 10 microns.

4. Disodium cromoglycate according to Claim 1 10 and substantially as hereinbefore described in the Example.