Releasably bound active materials

Details Releasably bound active materials Releasably bound active materials

1992-12-18

1994-12-27

Kishore, G. S.

Drug, bio-affecting and body treating compositions

Preparations characterized by special physical form

Particulate form

424490, 424458, A61K 914

Patent

active

053763858

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to a process for releasably binding active materials in non-aqueous media.
It is well known to bind active materials in a binder to improve various characteristics such as attrition resistance, moderation of activity, ease of handling and reduction of dust problems. There are several methods of achieving such binding which include compaction, pelletisation, granulation, extrusion/ spheronisation and the like. A good summary of such techniques can be found in Kirk-Othmer's Encyclopaedia of Chemical Technology, Vol. 21, pp 77-102 under the section headed `Size Enlargement`.
Amongst the various techniques employed granulation and extrusion/spheronisation are particularly useful and advantageous.
Granulation is a process for binding active material powders together into e.g. agglomerates. This technique usually mitigates problems of dust and materials handling and bestows other advantages such as improvement of flow; prevention of lump or cake formation; ease of metering, dosing and dispensing; enabling formation of uniform mixtures/blends without risk of segregation of the components in the mixture/blend; stabilisation of the active materials against premature degradation; controlling the release profile of the active materials; and enabling coatings to be applied on the active materials. Hitherto granulation techniques have mainly been carried out in aqueous systems, e.g. by mixing the active material with a binder and water to form a dough, shaping the dough into granules and drying the granules. Extrusion/spheronisation technique is used to convert an active material in powdered form into regular-sized, dense spheres. The purpose of this technique is usually to mitigate the problems of dust and materials handling, to allow complete and uniform mixing to be achieved with mixtures of powders without risk of segregation and to enable uniform coatings to be applied. As in the case of granulation, extrusion/spheronisation techniques have only been carried out hitherto in aqueous systems. Hence, the technique has been limited to treatment of active materials which are compatible with water. The technique consists essentially of (i) mixing a fine powder of the active material with a powdered binder and water to form a crumbly dough; (iii) extruding the dough to form tread-like material from the dough and (iii) placing the extrudate in a spheroniser so as to subject the extrudate to circular and tumbling motion whereby the extrudate is broken up into short pieces which then take the shape of a dense sphere.
By choice of appropriate formulations, the powders can be extruded into a smooth extrudate which (a) is friable, (b) does not crumble into a dusty powder in the spheroniser and (c) holds the moisture within the mixture thereby reducing stickiness and the risk of agglomeration. The extrusion/spheronisation technique is primarily used to produce spheres which are dense and have a tighter particle size distribution; have a relatively smooth surface; have complete and uniform mixing of the components without risk of segregation; facilitate application of coatings thereon; and protect the active material during storage and transportation.
In use, the spheres so produced are often required to disintegrate to deliver the active powder at the point of use.
In order to aid this disintegration, usually inorganic salts such as barium sulphate are used. In some cases surfactants are also used to help wetting of the spheres thereby aiding disintegration thereof in use. Swellable materials such as internally cross-linked cellulose have also been used to break up the spheres in use- Thus, the chosen formulation may contain several ingredients of which the active material content may vary from 0.1-99% w/w. The lower levels of loading within this range are used for highly potent active materials and where the required dosage rate is relatively low. Conversely, the higher loadings within this range are normally used when the required dosage rate is relatively high and/or the active material is of lo

REFERENCES:
patent: 4079125 (1978-03-01), Sipos
patent: 4309406 (1982-01-01), Guley et al.

Affiliated with

Also associated with

Rating

Releasably bound active materials does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Releasably bound active materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Releasably bound active materials will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-917409