Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Particulate form
Patent
1997-07-09
1999-04-06
Page, Thurman K.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Particulate form
424461, 424435, A61K 914
Patent
active
058914730
DESCRIPTION:
BRIEF SUMMARY
This application is the national phase of international application PCT/EP95/03560 filed Sep. 9. 1995 WO90/09033, Mar. 28, 1996 which designated the U.S.
FIELD OF THE INVENTION
The present invention relates to granular compositions which provide useful sensorially-perceived benefits in toothpaste compositions.
BACKGROUND OF THE INVENTION
The use of water as a binder for silica particles has been disclosed in GB1,365,516 and water is known as a common binder for size enlargement (Handbook of Powder Technology--Vol 1--Particle Size Enlargement--page 41, Table 2.3--Elsevier).
Toothpaste formulations containing a granular composition comprising a water insoluble material and a water insoluble binder have been disclosed in EP-B-269,966. Such granular composition can contain functional substances such as medicaments, enzymes and polishing agents. The problem addressed by this document is that it is not possible to bind the particles within the granular composition with water soluble binders for use in formulations containing large amounts of water, such as toothpastes. The reason being that the water soluble binder will dissolve in the aqueous component of the formulation and weaken the granular composition making it impossible to detect the coarse particles in the mouth.
The addition of a zinc salt, as an anti-plaque agent, into a toothpaste composition has already been disclosed in GB 1,373,001.
It has been found that granule compositions containing only water insoluble particulates of low to medium structure, particularly those with low oil absorption capacity favored as abrasives and polishing agents in dental formulations, bound together with water and dried are too weak to survive the normal processes in toothpaste manufacture and therefore would not be felt in the subsequent tooth cleaning process.
Additionally, granule compositions containing high structured water insoluble particulates (i.e. with high oil absorption capacity) for example silicas favored as thickening agents in toothpaste formulations, are considered to have too much strength and give unacceptable levels of mouthfeel.
To overcome this problem it has been discovered that granular compositions of sufficient strength can be prepared by mixing a high structured water insoluble particulate with a low to medium structured one prior to the binding process. Surprisingly the addition of powdered therapeutic agents e.g. zinc citrate, opacifiers e.g. titanium dioxide and coloured pigments have been shown to have no significant detrimental effect on the properties of the granular composition.
STANDARD PROCEDURES
The granular compositions of the invention are defined in terms of the properties and texture of the water insoluble particulates used to produce the agglomerate, its particle size distribution, and strength.
The oil absorption is determined by the ASTM spatula rub-out method (American Society Of Test Material Standards D, 281).
The test is based on the principle of mixing linseed oil with the water insoluble particulate by rubbing with a spatula on a smooth surface until a stiff putty-like paste is formed which will not break or separate when it is cut with a spatula. The volume of oil used is converted to weight and expressed as g of oil/100 g of water insoluble particulate.
The weight mean particle size of the water insoluble particulate before agglomeration is determined using a Malvern Mastersizer model X, made by Malvern Instruments, Malvern, Worcestershire with MS15 sample presentation unit. This instrument uses the principle of mie scattering, utilising a low power He/Ne laser. The water insoluble particulates are dispersed ultrasonically in water for 5 minutes to form an aqueous suspension and then mechanically stirred before they are subjected to the measurement procedure outlined in the instruction manual for the instrument, utilising a 45 mm lens in the detector system.
The Malvern Particle Sizer measures the weight particle size of the water insoluble particulate. The weight mean particle size (d.sub.50) or 50 percentil
REFERENCES:
patent: 4089943 (1978-05-01), Roberts et al.
patent: 5286480 (1994-02-01), Boggs et al.
patent: 5380530 (1995-01-01), Hill
Benston, Jr. William E.
Crosfield Limited
Page Thurman K.
LandOfFree
Granular Compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Granular Compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Granular Compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1368872