Methods of evaluating small molecule-modified polymers in compositions
Described herein are methods for evaluating polymer compositions comprising polymers modified with a small molecule compound (e.g., afibrotic compound), including methods for determining the concentration levels of said compounds.
1 . A method of evaluating a polymer composition, wherein the polymer composition comprises a polymer modified with:
(i) a compound of Formula (I-b):
or a pharmaceutically acceptable salt thereof, wherein:
Ring M 1 is aryl or heteroaryl, wherein each aryl and heteroaryl is optionally substituted with one or more R 3 ;
Ring Z 1 is cycloalkyl, heterocyclyl, aryl, or heteroaryl, wherein each cycloalkyl, heterocyclyl, aryl, or heteroaryl is optionally substituted with 1-5 R 5 ;
each of R 2a , R 2b , R 2c , and R 2d is independently hydrogen, alkyl, or heteroalkyl, or each of
R 2a and R 2b or R 2c and R 2d is taken together to form an oxo group;
X is absent, O, or S;
each R 3 and R 5 is independently alkyl, heteroalkyl, halogen, oxo, —OR A1 , —C(O)OR A1 , or —C(O)R B1 , wherein each alkyl and heteroalkyl is optionally substituted with one or more halogen, oxo, cyano, cycloalkyl, or heterocyclyl; or two R 5 are taken together to form a 5-6 membered ring fused to Ring Z 1 ;
R C is hydrogen or alkyl;
each R A1 and R B1 is independently hydrogen, alkyl, or heteroalkyl;
m and n are each independently 1, 2, 3, 4, 5, or 6; and
“ ” refers to a connection to the polymer; or
(ii) a compound of Formula (III-a):
or a pharmaceutically acceptable salt thereof, wherein:
Ring Z 2 is cycloalkyl, heterocyclyl, aryl, or heteroaryl, each of which is optionally substituted with 1-5 R 5 ;
each of R 2a , R 2b , R 2c , and R 2d is independently hydrogen, alkyl, heteroalkyl, halo; or
R 2a and R 2b or R 2c and R 2d are taken together to form an oxo group;
each of R 3 and R 5 is independently alkyl, heteroalkyl, halogen, oxo, —OR A1 , —C(O)OR A1 , or —C(O)R B1 ;
each R A1 and R B1 is independently hydrogen, alkyl, or heteroalkyl;
m and n are each independently 1, 2, 3, 4, 5, or 6;
and p are each independently 0, 1, 2, 3, 4, or 5;
q is an integer from 0 to 25; and
“ ” refers to a connection to the polymer;
the method comprising:
(a) subjecting the polymer composition to reaction conditions that allow for release of the compound of Formula (I-b) or Formula (III-a) from the polymer; and
(b) acquiring a value of concentration of the compound of Formula (I-b) or Formula (III-a) bound to the polymer,
thereby evaluating the polymer composition.
2 . The method of claim 1 , wherein the polymer in the polymer composition is a polysaccharide.
3 . The method of claim 2 , wherein the polysaccharide is an alginate.
4 . The method of claim 3 , wherein the alginate:
(i) has an average molecular weight of 75 kD to 150 kD; or
(ii) has a guluronate to mannuronate (G:M) ratio of greater than or equal to 1.5.
5 . The method of claim 1 , wherein the compound of Formula (I-b) or Formula (III-a) is covalently bound to the polymer in the modified polymer.
6 . The method of claim 1 , wherein the polymer composition comprises a single type of modified polymer.
7 . The method of claim 1 , wherein the compound of Formula (I-b) or Formula (III-a) is a compound selected from:
Compound No.
Structure
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
8 . The method of claim 1 , wherein the reaction conditions in step (a) comprise:
(i) contacting the polymer composition with an acidic solution; or
(ii) heating the polymer composition; or
(iii) exposing the polymer composition to microwave irradiation.
9 . The method of claim 1 , further comprising a separation step.
10 . The method of claim 9 , wherein the separation step occurs between step (a) and step (b).
11 . The method of claim 9 , wherein the separation step comprises chromatography.
12 . The method of claim 1 , wherein acquiring a value of concentration in step (b) comprises: (i) determining an area of a chromatogram peak for the compound of Formula (I-b) or Formula (III-a) and (ii) comparing an area of a chromatogram peak with a standard.
13 . The method of claim 1 , further comprising acquiring a value of concentration of an unconjugated compound of Formula (I-b) or an unconjugated compound of Formula (III-a) in the polymer composition.
14 . The method of claim 13 , wherein acquiring a value of concentration of the unconjugated compound of Formula (I-b) or the unconjugated compound of Formula (III-a) in the polymer composition comprises:
(a′) separating the polymer composition into a polymer bound fraction and a non-polymer bound fraction;
(b′) retaining the non-polymer bound fraction; and
(c′) acquiring a value of concentration of the unconjugated compound of Formula (I-b) or the unconjugated compound of Formula (III-a) in the non-polymer bound fraction.
15 . The method of claim 14 , wherein the separating of step (a′) comprises filtration.
16 . The method of claim 14 , wherein step (c′) comprises a separation step.
17 . The method of claim 16 , wherein the separation step comprises chromatography.
18 . The method of claim 14 , wherein acquiring a value of concentration in step (c′) further comprises: (i) determining an area of a chromatogram peak of a sample of the unconjugated compound of Formula (I-b) or the unconjugated compound of Formula (III-a) in the non-polymer bound fraction and (ii) comparing an area of a chromatogram peak with a standard.
19 . The method of claim 1 , wherein evaluating a polymer composition comprises determining concentration of a compound of Formula (I-b) or Formula (III-a) bound to a modified polymer in the polymer composition.
20 . The method of claim 19 , wherein determining concentration of a compound of Formula (I-b) or Formula (III-a) bound to a modified polymer in the polymer composition comprises:
(a″) acquiring a value for total concentration of the compound of Formula (I-b) or Formula (III-a) in the polymer composition;
(b″) acquiring a value for concentration of an unconjugated compound of Formula (I-b) (or an unconjugated compound of Formula (III-a) in the polymer composition; and/or
(c″) subtracting the value of concentration of the unconjugated compound of Formula (I-b) or the unconjugated compound of Formula (III-a) from the value of total concentration of the compound of Formula (I-b) or Formula (III-a) in the polymer composition,
thereby determining the concentration of the compound of Formula (I-b) or Formula (III-a) bound to a modified polymer in the polymer composition.