De Montfort University

Margaret Joan Taylor

The present invention relates to a gel having a three dimensional matrix structure and a drug in the form of a solid contained within the three dimensional matrix. Gels of the invention are preferably for implantation into a patient. Storing the drug as a solid within the gel means that the drug density is high in those areas of the gel which contain solid drug. The high drug density means that a larger amount of drug can be stored in a gel of a given size relative to the amount of drug that can be stored as individual molecules. The large deposit of solid drug means that the gel can sustain release of the drug for an extended period of time. This is advantageous because it minimises the frequency of replacement or replenishment of the implanted gel, thereby minimising discomfort and inconvenience to the patient.

Matrix gel

The present invention relates to a container for an analyte-sensitive gel. When analyte contacts such a gel it causes a gel-sol transition resulting in decreased viscosity of the gel. Such gels can be used for controlling the rate of release of an agent from a reservoir in response to the concentration of an analyte. The container is configured to allow analyte to pass into the container and contact the gel and to allow agent to diffuse out of the container. Such a container may be implantable in the body of a subject and therefore it is preferred if the container is constructed from materials that can be tolerated by the body for a period of time. Advantageously, the container limits the swelling and dilution of gel contained within the container caused by the influx of water into the gel by osmosis. The container therefore maintains the gel in a desired conformation and ensures a predictable release profile of the agent.

Container

The present invention relates to a gel composition, comprising first and second gel-forming moieties which bind reversibly to one another to form a gel. The binding of the moieties is sensitive to the level of an analyte, and either or both of the gel-forming moieties are attached to cross-linked particulate entities such that the interstices between the entities allow gel-sol and sol-gel transformation, and yet are not so small that the analyte cannot diffuse therethrough. The invention also provides drug delivery systems and sensors for detecting an analyte utilizing such a gel.

Gel compositions

A method for producing a drug system which is a reversible gelled matrix with entrapped drug. The gel is made by combining a polysaccharide, such as dextran, a polymer of glucose, with a natural macromolecule, such as the lectin, concanavalin A, with binding sites for monomers of the polysaccharide. The drug is released in response to exposure of the matrix to free carbohydrate containing the monomer of the polysaccharide for which the natural macromolecule binds.

Method of making a reversible matrix drug delivery system

There is disclosed a method for producing a system for delivering a drug for the treatment of a condition, comprising immobilizing a drug or other agent in a bio-compatible matrix containing at least one receptor for a physiological substance which will be in the environment of the matrix when administered, said receptor being anchored within the matrix but remaining biologically active being activated in response to the levels of said physiological substance to effect a conformational change in the matrix allowing mobilization and release of the drug only into the environment.

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Leicester, United Kingdom

Margaret Joan Taylor