Biodegradable polypeptide and its use for the gradual release of drugs

Claim 2

A poilypeptide selected from the group consisting of (a) biodegradable polymers with the formula ##STR11## in which R 1 and R 2 are selected from the group consisting of lower alkyl and hydrogen; and R is lower alkyl or an aromatic radical; or R 2 is lower alkyl or hydrogen and R and R 1 are interlinked in the form of a substituted or non-substituted ethylene or vinylene bridge; and (b) polymers with the formula ##STR12## in which groups R, R 1 and R 2 have the values given above and where R' is a free or partially or completely esterified amino-acid radical; y and z are integers, n is 1 or 2; and x is equal to y+z and is selected so that the molecular mass of the polypeptide is not lower than 5000D.

Claim 3

Polypeptide according to claim 1 wherein R is selected from the group consisting of methyl, ethyl, isopropyl, isobutyl, tert-butyl, phenyl and benzyl radicals.

Claim 4

Polypeptide according to claim 1 wherein R and R 1 are interconnected to form a link selected from the following formulae: --CH 2 --; --C═CH--; --CH(CH 3 )--CH(CH 3 ); --C(CH 3 )═C(CH 3 )--; 1.2-phenylene; cyclohexenylene; cyclopentenylene, cyclopentadienylene.

Claim 5

Polypeptide according to claim 1 wherein polymer (I) is selected from acyl- and aryloxymethyl glutamates and aspartates and polymers (II) is selected from acyl- and aryloxymethyl glutamate or aspartate copolymers with one or more other amino-acids selected from alanine, leucine, valine and phenylalaline.

Claim 6

Polypeptide according to claim 1 wherein polymers (II) is a glutamate or aspartate copolymer with at least one member of the group consisting of glutamic acid, lower alkyl glutamates, aspartic acid and lower alkyl aspartates.

Claim 7

Polypeptide according to claim 4 wherein the acyl groups are selected from acetyl, propionyl, butyryl, isobutyryl, pivaloyl, benzoyl, and phenylacetyl groups.

Claim 8

A drug composition comprising a polypeptide selected from the group consisting of (a) biodegradable polymers with the formula ##STR13## in which R 1 and R 2 are selected from the group consisting of lower alkyl and hydrogen; and R is lower alkyl or an aromatic radical; or R 2 is lower alkyl or hydrogen and R and R 1 are interlinked in the form of a substituted or non-substituted ethylene or vinylene bridge; and (b) polymers with the formula ##STR14## in which groups R, R 1 and R 2 have the values given above and where R 1 is a free or partially or completely esterified amino-acid radical; y and z are integers, n is 1 or 2, and x is equal to y+z and is selected so that the molecular mass of the polypeptide is not lower than 5000D, and a drug, the polypeptide serving as a drug reservoir with a delay effect, the drug being released progressively to its destination consequent upon the biodegradation of the polypeptide.

Claim 9

A drug composition comprising a polypeptide selected from the group consisting of (a) biodegradable polymers with the formula ##STR13## in which R 1 and R 2 are selected from the group consisting of lower alkyl and hydrogen; and R is lower alkyl or an aromatic radical; or R 2 is lower alkyl or hydrogen and R and R 1 are interlinked in the form of a substituted or non-substituted ethylene or vinylene bridge; and (b) polymers with the formula ##STR14## in which groups R, R 1 and R 2 have the values given above and where R 1 is a free or partially or completely esterified amino-acid radical; y and z are integers, n is 1 or 2, and x is equal to y+z and is selected so that the molecular mass of the polypeptide is not lower than 5000D, and a drug, the polypeptide serving as a drug reservoir with a delay effect, the drug being released progressively to its destination consequent upon the biodegradation of the polypeptide.

Claim 10

A composition according to claim 7 wherein the drug and the said polypeptide are mixed homogeneously and shaped in a pharmaceutically acceptable form.

Claim 11

A composition according to claim 8 which includes polyalkylene glycol to plasticise the polypeptide.

Claim 12

A biodegradable implant or prosthetic comprising the composition of claim 7.

Claim 13

In a method of administering a drug by release from a biodegradable polymer carrying the drug, the improvement which comprises using a polypeptide selected from the group consisting of (a) biodegradable polymers with the formula ##STR15## in which R 1 and R 2 are selected from the group consisting of lower alkyl and hydrogen; and R is lower alkyl or an aromatic radical; or R 2 is lower alkyl or hydrogen and R and R 1 are interlinked in the form of a substituted or non-substituted ethylene or vinylene bridge; and (b) polymers with the formula ##STR16## in which groups R, R 1 and R 2 have the values given above and where R 1 is a free or partially or completely esterified amino-acid radical; y and z are integers, n is 1 or 2, and x is equal to y+z and is selected so that the molecular mass of the polypeptide is not lower than 5000D, as the carrier for the drug.

Claim 14

In a method of administering a drug by release from a biodegradable polymer carrying the drug, the improvement which comprises using a polypeptide selected from the group consisting of (a) biodegradable polymers with the formula ##STR15## in which R 1 and R 2 are selected from the group consisting of lower alkyl and hydrogen; and R is lower alkyl or an aromatic radical; or R 2 is lower alkyl or hydrogen and R and R 1 are interlinked in the form of a substituted or non-substituted ethylene or vinylene bridge; and (b) polymers with the formula ##STR16## in which groups R, R 1 and R 2 have the values given above and where R 1 is a free or partially or completely esterified amino-acid radical; y and z are integers, n is 1 or 2, and x is equal to y+z and is selected so that the molecular mass of the polypeptide is not lower than 5000D, as the carrier for the drug.