Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
176 words
A biocompatible and/or biodegradable implant for controlled release, by diffusion, of a therapeutic agent into an outside medium at a site of the implant which comprises a body consisting of: a core defining a solid mass having walls and being formed of a first biocompatible and/or biodegradable polymeric material, said core having embedded therein a plurality of granules of the therapeutic agent and said core allowing for diffusion of the therapeutic agent into the outside medium; and a coating of a second biocompatible and/or biodegradable polymeric material which prevents the diffusion of the therapeutic agent into the outside medium, said coating covering all but one of the walls of the solid mass; wherein the degradation half-lifes of the first and the second polymeric materials are longer than diffusion half-life of the therapeutic agent when biodegradable polymers are used; and further wherein the size of the granules increase from the one uncovered wall to an opposite wall thereof, thus providing, in the core, a concentration gradient allowing controlled diffusion of the therapeutic agent from the uncovered wall.
Claim 2
Dependent Claim
176 words
A biocompatible and/or biodegradable implant for controlled release, by diffusion, of a therapeutic agent into an outside medium at a site of the implant which comprises a body consisting of: a core defining a solid mass having walls and being formed of a first biocompatible and/or biodegradable polymeric material, said core having embedded therein a plurality of granules of the therapeutic agent and said core allowing for diffusion of the therapeutic agent into the outside medium; and a coating of a second biocompatible and/or biodegradable polymeric material which prevents the diffusion of the therapeutic agent into the outside medium, said coating covering all but one of the walls of the solid mass; wherein the degradation half-lifes of the first and the second polymeric materials are longer than diffusion half-life of the therapeutic agent when biodegradable polymers are used; and further wherein the size of the granules increase from the one uncovered wall to an opposite wall thereof, thus providing, in the core, a concentration gradient allowing controlled diffusion of the therapeutic agent from the uncovered wall.
Claim 3
Dependent Claim
13 words
A device as defined in claim 1, wherein said polymeric material is poly(ε-caprolactone).
Claim 4
Dependent Claim
31 words
A device as defined i claim 1, wherein said mass is cylindrically shaped and wherein said uncovered wall is one of the two opposite end walls of the cylindrically shaped mass.
Claim 5
Dependent Claim
167 words
A method for the production of a biocompatible and/or biodegradable implant, according to claim 1, for controlled release, by diffusion, of a therapeutic agent into an outside medium at a sit of the implant, aid implant including a core defining a solid mass having walls and being formed of a first biocompatible and/or biodegradable polymeric material, said implant also including a coating of a second biocompatible and/or biodegradable polymeric material which prevents diffusion of the therapeutic agent into the outside medium, said method comprising the steps of: (a) heating a mixture of said therapeutic agent and said first polymeric material to obtain a liquid state or a semi-solid state; (b) removing air bubbles from the mixture under vacuum; (c) sedimenting the mixture freed of air bubbles by step (b) in a container to obtain a matrix; (d) cutting the container and removing the matrix obtained in step (c) to form the core; and (e) covering all but one of said walls of said core with said coating.
Claim 6
Dependent Claim
21 words
The method of claim 4, wherein the sedimenting in step (c) is accomplished by centrifuging the mixture freed of air bubbles.