Biodegradable, implantable drug delivery device, and process for preparing and using the same

Claim 2

An implant device for the controllable release of at least one substance into a living host into which it is implanted, comprising (a) a substance to be released within a living host; and (b) a matrix material prepared from a block copolymer of the formula ##STR6## where R 1 , R 2 , R 3 and R 4 are ##STR7## and m, n, p and q range between 1 and 100, or a copolymer of two or more α-amino acids distributed at random along the chain of the formula ##STR8## wherein R 1 and R 2 are defined above, which is biocompatible and biodegradable within the host environment into which it is implanted; does not form covalent bonds with said substance to be released; has an average molecular weight of 20,000 to 1,000,000; and is essentially free of any carrier of said substance, said substance being distributed within said matrix to provide a controlled rate of release for systemic utilization within said host by diffusion, hydrolysis or a combination thereof of said matrix material said implant device being shaped as an injectable configuration.

Claim 3

An implant device in accordance with claim 1 wherein said copolymer is formed of γ-benzyl-L-glutamate and L-leucine.

Claim 4

An implant device in accordance with claim 1 wherein said copolymer is formed of L-glutamic acid and L-leucine.

Claim 5

An implant device in accordance with claim 1 wherein said substance is physically admixed throughout said matrix.

Claim 6

An implant device in accordance with claim 1 wherein said implant device contains a pluraity of said substances for release in sequence.

Claim 7

An implant device in accordance with claim 1 wherein said matrix structure is configured as a rod.

Claim 8

An implant device in accordance with claim 6 wherein said rod is formed as a core with at least one layer of said matrix material built up thereon, said core and each layer having a predetermined concentration of said substance distributed therein.

Claim 9

An implant device in accordance with claim 6 wherein said rod is formed with an axial opening therethrough, thereby defining an internal surface as well as an external surface.

Claim 10

An implant device in accordance with claim 6 wherein said rod is formed as a sealed tube.

Claim 11

An implant device in accordance with claim 9 wherein said sealed tube comprises an outer casing formed of said matrix material and an inner core comprising said substance to be released.

Claim 12

An implant device in accordance with claim 10 wherein said core is formed of said copolymer acid component having said substance physically admixed therethrough.

Claim 13

An implant device in accordance with claim 11 wherein said inner core comprises up to about 90% by weight of said substance.

Claim 14

An implant device in accordance with claim 1 wherein said matrix structure is configured as an essentially spherical microcapsule.

Claim 15

An implant device in accordance with claim 13 wherein said microcapsule comprises a core with a coating of essentially pure copolymer acid.

Claim 16

An implant device in accordance with claim 14 wherein said core is formed of said copolymer acid component having said substance physically admixed therethrough.

Claim 17

An implant device in accordance with claim 1 wherein said substance is a drug.

Claim 18

An implant device in accordance with claim 16 wherein said drug is a fertility control agent.

Claim 19

An implant device in accordance with claim 17 wherein said fertility control agent is progesterone.

Claim 20

An implant device in accordance with claim 16 wherein said drug is a narcotic antagonist.

Claim 21

An implant device in accordance with claim 19 wherein said narcotic antagonist is naltrexone.

Claim 22

A process for delivering at least one substance at a controllable release rate into a living host, comprising implanting into said host an implant device, comprising (a) a pharmaceutically effective quantity of a substance to be released within a living host; and (b) a matrix material prepared from a block copolymer of the formula ##STR9## where R 1 , R 2 , R 3 and R 4 are ##STR10## and m, n, p and q range between 1 and 100, or a copolymer of two or more α-amino acids distributed at random along the chain of the formula ##STR11## wherein R 1 and R 2 are defined above which is biocompatible and biodegradable within the host environment into which it is implanted; does not form covalent bonds with said substance to be released; has an average molecular weight of 20,000 to 1,000,000; and is essentially free of any carrier for said substance, said substance being distributed within said matrix to provide a controlled rate of release for systemic utilization within said host by diffusion, hydrolysis or a combination thereof of said matrix material, said implant device being shaped as an injectable configuration.

Claim 23

A process for delivering at least one substance at a controllable release rate into a living host, comprising implanting into said host an implant device, comprising (a) a pharmaceutically effective quantity of a substance to be released within a living host; and (b) a matrix material prepared from a block copolymer of the formula ##STR9## where R 1 , R 2 , R 3 and R 4 are ##STR10## and m, n, p and q range between 1 and 100, or a copolymer of two or more α-amino acids distributed at random along the chain of the formula ##STR11## wherein R 1 and R 2 are defined above which is biocompatible and biodegradable within the host environment into which it is implanted; does not form covalent bonds with said substance to be released; has an average molecular weight of 20,000 to 1,000,000; and is essentially free of any carrier for said substance, said substance being distributed within said matrix to provide a controlled rate of release for systemic utilization within said host by diffusion, hydrolysis or a combination thereof of said matrix material, said implant device being shaped as an injectable configuration.

Claim 24

A process in accordance with claim 21 wherein said implant device releases a plurality of said substances in sequence.

Claim 25

A process in accordance with claim 21 wherein said matrix structure is configured as a rod.

Claim 26

A process in accordance with claim 23 wherein said rod is formed as a core with at least one layer of said matrix material built up thereon, said core and each layer having a predetermined concentration of said substance distributed therein.

Claim 27

A process in accordance with claim 23 wherein said rod is formed with an axial opening therethrough, thereby defining an internal surface as well as an external surface.

Claim 28

A process in accordance with claim 23 wherein said rod is formed as a sealed tube.

Claim 29

A process in accordance with claim 26 wherein said sealed tube comprises an outer casing formed of said matrix material and an inner core comprising said substance to be released.

Claim 30

A process in accordance with claim 27 wherein said core is formed of said poly-α-amino acid component having said substance physically admixed therethrough.

Claim 31

A process in accordance with claim 28 wherein said inner core comprises up to about 90% by weight of said substance.

Claim 32

A process in accordance with claim 2 wherein said matrix structure is configured as an essentially spherical microcapsule.

Claim 33

A process in accordance with claim 30 wherein said microcapsule comprises a core with a coating of essentially pure copolymer acid.

Claim 34

A process in accordance with claim 3 wherein said core is formed of said poly-α-amino acid component having said substance physically admixed therethrough.

Claim 35

A process in accordance with claim 2 wherein said substance is a drug.

Claim 36

A process in accordance with claim 33 wherein said drug is a fertility control drug.

Claim 37

A process in accordance with claim 34 wherein said fertility control drug is progesterone.

Claim 38

A process in accordance with claim 33 wherein said drug is a narcotic antagonist.

Claim 39

A process in accordance with claim 36 wherein said narcotic antagonist is naltrexone.

Claim 40

An implant device in accordance with claim 3 wherein the mole ratio of said L-glutamic acid to said L-leucine ranges between about 10 to 90 and 40 to 60.