Drug delivery system
AssigneeBayer Aktiengesellschaft
InventorsHeikki Lyytikäinen, Harri Jukarainen
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Abstract
The present invention provides a novel drug delivery system for the controlled release of therapeutically active substances at a predetermined, essentially constant release rate over a prolonged period of time. The delivery system comprises at least one core comprising said therapeutically active substance(s), at least one membrane encasing the core and an intermediary layer of a substantially inert material, wherein the intermediary layer is applied between the core and the membrane or between two membrane layers.
Claims12
A drug delivery system comprising at least one core comprising Levonorgestrel and at least one membrane encasing the core, wherein the system further comprises an intermediary layer consisting of a substantially inert material and optionally a liquid solvent or silicone oil, wherein the intermediary layer is not covalently bound to the material of the core and is not covalently bound to the material of the at least one membrane and the substantially inert material is selected from the group consisting of silica, and fumed and precipitated silicas to maintain at least substantially constant release of the Levonorgestrel during course of usage with no or diminished initial burst as compared to a delivery system without the intermediary layer, wherein the drug delivery system has a release rate that is relatively constant for from 1 week to 7 years.
Dependencies are inferred from the claim text.