Patent ID: 7902319

Claim:
A compound of formula I or a pharmaceutically acceptable salt thereof: [R′—(Y) p —O] q —Ar—[O—(X) r —R′] s I wherein: Ar is the aromatic portion of a diphenol; X and Y are independently selected from: —CH 2 COO—; —CH(CH 3 )COO—; —CH 2 CH 2 OCH 2 COO—; —CH 2 CH 2 CH 2 CH 2 CH 2 COO—; —(CH 2 ) y COO— where y is independently selected from 2-4 and 6-24; and —(CH 2 CH 2 O) z CH 2 COO— where z is independently selected from 2-24; provided that the groups represented by [R′—(Y) p —O] q — and —[O—(X) r —R′] s are different from one another; R′ is selected from H, benzyl, and C 1-6 alkyl; p is selected from 1, 2, 3, 4, 5, and 6; q is selected from 1, 2, and 3; r is selected from 1, 2, 3, 4, 5, and 6; and s is selected from 1, 2, and 3.