Controlled release composition

a technology of composition and controlled release, which is applied in the field of composition, can solve the problems of short half-life in the body, difficult to maintain a constant concentration of active substances, and unstable hydrolysis of active substances in aqueous environments, and achieve the effect of constant rate of release and easy follow-up of patients' prescribed regimens

US20080254124A1Inactive Publication Date: 2008-10-16EGALET LTD
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Patent Information

Authority / Receiving Office
US · United States
Patent Type
Applications(United States)
Current Assignee / Owner
Publication Date
2008-10-16
Estimated Expiration
Not applicable · inactive patent
Patent Text Reader

Abstract

A composition for controlled delivery of at least one active substance into an aqueous medium by erosion at a preprogrammed rate of at least one surface of the composition, comprising a matrix comprising the active substance, the matrix being erodible in the aqueous medium in which the composition is to be used, and a coating having at least one opening exposing at least one surface of said matrix, the coating comprising a first cellulose derivative which has thermoplastic properties and which is substantially insoluble in the aqueous medium in which the composition is to be used, and at least one of a second cellulose derivative which is soluble or dispersible in water, a plasticizer, and a filler. The coating is a coating which crumbles and / or erodes upon exposure to the aqueous medium such as a body fluid. The first cellulose derivative may be, e.g., ethylcellulose, cellulose acetate, cellulose propionate or cellulose nitrate, and the second cellulose derivative may be, e.g. methylcellulose, carboxymethylcellulose or salts thereof, cellulose acetate phthalate, microcrystalline cellulose, ethylhydroxyethylcellulose, ethylmethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxymethylcellulose or hydroxymethylpropylcellulose.
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Description

FIELD OF THE INVENTION

[0001] The present invention relates to a composition for controlled delivery of an active substance into an aqueous medium.BACKGROUND OF THE INVENTION

[0002] It is known to obtain sustained release of an active substance, e.g. a pharmaceutically active powder, by embedding it in a matrix of an insoluble substance from which the active substance will gradually diffuse. Sustained release of an active substance contained in a tablet core may also be achieved by applying to the core a semi-permeable coating through which water and dissolved active substance may diffuse or an insoluble coating provided with a hole through which the active substance is released. Gradual release of an active substance may furthermore be obtained by microencapsulating particles of an active substance in one or more layers of film which may be of different types, e.g. of a type which mediates diffusion of the active substance or release thereof in the intestines.

[0003] These conventional w...

Examples

example 1

[0057]A composition according to the invention was prepared from the following ingredients:

% by weightCoatingEthylcellulose (Dow Chem. Co.)50(ethoxyl content 45-46.5%)Hydroxymethylcellulose20Carboxymethylcellulose5Cetostearyl alcohol20Titanium dioxide5MatrixPolyethylene glycol 35,00050Polyethylene glycol 200010stearatePotato starch39Tartrazine1

[0058]The coating was prepared by first mixing the ethylcellulose with the hydroxymethylcellulose, carboxymethylcellulose and titanium dioxide, after which melted cetostearyl alcohol was added. After mixing in a high speed dry mixer (Robot Coupe) for about 2 minutes, the mixture was dried in an oven at 100° C. for about 30 minutes. The mixture was then allowed to cool to room temperature, after which it had a suitable consistency for being fed into an injection moulding machine.

[0059]The matrix was prepared by first mixing the PEG 35,000, the potato starch and the tartrazine together in a high speed dry mixer (Robot Coupe). The PEG 2000 steara...

example 2

[0063]A composition according to the invention was prepared from the following ingredients:

% by weightCoatingEthylcellulose (Dow Chem. Co.)50(ethoxyl content 45-46.5%)Hydroxymethylcellulose17.5Carboxymethylcellulose7.5Cetostearyl alcohol20Titanium dioxide5MatrixPolyethylene glycol 35,00037Polyethylene glycol 200010stearatePotato starch49Tartrazine1Hydroxymethylcellulose3

[0064]The coating was prepared as described above in Example 1.

[0065]The matrix was also prepared as described above in Example 1, the hydroxymethylcellulose being mixed together with the PEG 35,000, the potato starch and the tartrazine in the initial mixing step.

[0066]A composition having the same dimensions as that of Example 1 was prepared as described in Example 1.

[0067]Also the coating and matrix mixtures of this Example were easy to feed into the injection moulding machine and performed well in the mould. An analysis (using the method described in Example 1) of the dissolution of the composition showed a zero o...