Drug – bio-affecting and body treating compositions – Designated organic nonactive ingredient containing other... – Aftertreated solid synthetic organic polymer
Reexamination Certificate
2001-05-31
2004-02-24
Webman, Edward J. (Department: 1617)
Drug, bio-affecting and body treating compositions
Designated organic nonactive ingredient containing other...
Aftertreated solid synthetic organic polymer
C514S272000, C525S419000, C525S450000
Reexamination Certificate
active
06696500
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sustained-release preparation comprising a bioactive substance having an acidic group and a biodegradable polymer having an optionally protected basic group.
2. Description of the Related Art
To develop an excellent sustained-release preparation comprising a bioactive substance, various attempts have been made in the field of the manufacturing pharmacy, in consideration of the physical properties of the substance. A currently available method of preparing a sustained-release preparation of a bioactive substance having an acidic group is described in Japanese Patent Unexamined Publication No. 124814/1990, in which an acidic water-soluble drug is encapsuled in a microcapsule having a polymer as the wall material and incorporating a basic substance as a drug-retaining agent.
The Journal of the Korean Chemical Society, Vol. 34, No. 2, pp. 203-210 (1990) describes as a synthesis intermediate a compound wherein 3-amino-1-propanol is bound to the terminal carboxyl group of poly(1-lactide) via ester linkage.
The Journal of Macromol Chem., 196, 3891-3903(1995) discloses a poly(L-lactic acid)-OCH
2
CH
2
CH
2
—NH
2
and synthesis thereof as a initiator for the polymerization of N-carboxyanhydrides in the synthesis of poly(L-lactide)-block-poly(&agr;-amino acid)s.
J. POLYM. SCI. PART A: POLYM. CHEM., 31, 275-278(1993) discloses &ohgr;-amino poly(&egr;-caprolactone) as a synthesis intermediate.
WO 94/21229 describes an aerosol composition containing a dispersion aid comprising a polymer having an amino acid bound to at least one terminal.
Although serving well as bases for sustained-release preparations of basic drugs, biodegradable polymers such as lactic acid-glycolic acid copolymer are unsatisfactory in terms of bioactivity retention, incorporation rate, suppression of drug leakage early after administration, constant sustained release for an extended period of time, and others, as bases for sustained-release preparations of bioactive substances having an acidic group.
SUMMARY OF THE INVENTION
Through extensive investigation aiming at creating a sustained-release preparation of acidic drug having excellent sustained-release property, the present inventors found that the use of a biodegradable polymer wherein a basic group is introduced as a base for sustained-release preparation results in an improved microcapsule incorporation rate and suppressed leakage early after administration, without loss of the activity of a bioactive substance having an acidic group, and ensures constant sustained release for an extended period of time. The present inventors made further investigation based on this finding, and developed the present invention.
Accordingly, the present invention relates to:
(1) a sustained-release preparation which comprises a bioactive substance having an acidic group and a biodegradable polymer having an optionally protected basic group,
(2) the sustained-release preparation according to term (1) above, wherein the polymer has at least an optionally protected basic group at a terminal,
(3) the sustained-release preparation according to term (1) above, wherein the polymer has an optionally protected basic group which is introduced to the terminal carboxyl group,
(4) the sustained-release preparation according to term (1) above, wherein the polymer has at a terminal a thioesterified, esterified or amidated carboxyl group having an optionally protected basic group,
(5) the sustained-release preparation according to term (1) above, wherein the biodegradable polymer is an aliphatic polyester,
(6) the sustained-release preparation according to term (5) above, wherein the aliphatic polyester is an &agr;-hydroxycarboxylic acid polymer,
(7) the sustained-release preparation according to term (5) above, wherein the aliphatic polyester is a homopolymer or copolymer of lactic acid and glycolic acid,
(8) the sustained-release preparation according to term (7) above, wherein the weight-average molecular weight of the homopolymer or copolymer of lactic acid and glycolic acid is not less than about 2,000,
(9) the sustained-release preparation according to term (7) above, wherein the lactic acid/glycolic acid content ratio is about 100/0 to about 30/70 (mol/mol %),
(10) the sustained-release preparation according to term (1), wherein the basic group is (i) a cyclic amino group, (ii) a nucleic acid base or (iii) a hydrocarbon group having 1 to 5 substituents selected from the group consisting of amino groups, amidino groups, guanidino groups, ammonium groups, cyclic amino groups and nucleic acid bases, each of which may be substituted,
(11) A polymer having the formula: POLY-CO—NH—R′—X′ wherein POLY represents the principal chain of a polymer, R′ represents a divalent hydrocarbon group, X′ represents a basic group selected from amino groups, amidino groups, cyclic amino groups and nucleic acid bases each of which basic group may be protected,
(12) the polymer according to term (11) above, wherein POLY is a principal chain of a homopolymer or copolymer of an &agr;-hydroxycarboxylic acid,
(13) The polymer according to term (12) above, wherein the &agr;-hydroxycarboxylic acid is lactic acid and/or glycolic acid,
(14) the polymer according to term (11) above, wherein R′ is a C
1-15
hydrocarbon group,
(15) the polymer according to term (11), wherein X′ is an optionally protected amino group,
(16) a polymer having the formula: POLY-COO—R″—X′ wherein POLY represents the principal chain of a homopolymer or copolymer of &agr;-hydoxycarboxylic acid, R″ represent ethylene which may be substituted with C
1-4
alkyl; X′ represents a basic group selected from amino groups, amidino groups, cyclic amino groups and nucleic acid base, each of which basic group may be protected,
(17) a method of producing the polymer of term (11) above which comprises reacting a compound having the protected basic group of the formula H
2
N—R′—S′ with a polymer of the formula POLY-COOH or active derivative thereof,
(18) the method according to term (17) above, which further comprises deprotection reaction of the protected basic group of the polymer,
(19) a method of improving the sustained-release property of a sustained-release preparation for a bioactive substance having an acidic group by using a biodegradable polymer having an optionally protected basic group as a base thereof,
(20) a base for a sustained-release preparation of a bioactive substance having an acidic group, which comprises a biodegradable polymer having an optionally protected basic group, and
(21) use of a biodegradable polymer having an optionally protected basic group, for the production of a sustained-release preparation of a bioactive substance having an acidic group.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the present invention, the “biodegradable polymer” is not subject to limitation, as long as it becomes compatible with living tissue and exhibits no deleterious action on the living body after administration. The biodegradable polymer is more preferably one that is metabolically degraded in vivo and eventually excreted from the body, commonly used such biodegradable polymers including those that are sparingly soluble or insoluble in water. The biodegradable polymer is exemplified by those described in “Drug Delivery System, Chapter 3 (CMC, 1986).” Specifically, useful biodegradable include the following:
(1) Fatty acid polyesters:
(i) Polymers and copolymers synthesized from one or more &agr;-hydroxycarboxylic acids (e.g., glycolic acid, lactic acid, hydroxybutyric acid), hydroxydicarboxylic acids (e.g., malic acid), hydroxytricarboxylic acids (e.g., citric acid) etc., mixtures thereof, &bgr;-poly-&agr;-benzyl malate, poly-3-hydroxybutanoic acid.
(ii) Polymers and copolymers synthesized from one or more polylactides (e.g., glycolides, lactides, benzylmalolactonate, malide dibenzyl ester, 3-[(benzyloxycarbonyl)methyl]-1,4-dioxane-2,5-dione) etc., mixtures thereof.
(iii) Polymers
Hata Yoshio
Iinuma Satoshi
Sato Jun
Taira Hikaru
Takeda Chemical Industries Ltd.
Webman Edward J.
Wenderoth , Lind & Ponack, L.L.P.
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