Patent ID: 8519178

Claim:
A method for the purification of a prostaglandin by supercritical fluid chromatography, said method comprising using a stationary phase and a mobile phase comprising carbon dioxide, wherein the stationary phase is a non-chiral stationary phase selected from the group consisting of 4 ethyl pyridine, 2-ethyl pyridine and pyridine urea or a chiral stationary phase and the prostaglandin is a compound of formula (I), a compound of formula (II), or a compound of formula (IV): wherein, V is C; W is X is CONR 12 R 13 or CO 2 R 12 ; Y is Z is C 1-20 -alkyl, C 2-20 -alkynyl, —O—(C 6-20 -aryl) or —(C 1-20 -alkyl)-(C 5-20 -aryl), wherein the aryl group is optionally substituted with one to three substituents selected from the group consisting of C 1-20 -alkyl, halo and C(halo) 3 ; R 1 and R 2 are independently H or OH, or R 1 and R 2 together form R 3 and R 4 are independently H or OH; R 5 and R 6 are independently H or OH, or R 5 and R 6 together form R 7 and R 8 are independently H, OH, halo or C 1-20 -alkyl; R 9 and R 10 are independently H or C 1-20 -alkyl, wherein the alkyl group is optionally substituted with one or more substituents selected from CONR 12 R 13 , CO 2 R 12 , and CO 2 − -M + ; R 11 is C 1-20 -alkyl or —O—(C 1-20 -alkyl), wherein the alkyl group is optionally substituted with one or more substituents selected from CONR 12 R 13 , CO 2 R 12 , and CO 2 − -M + ; R 12 and R 13 are independently selected from the group consisting of H and C 1-20 alkyl; M + is a counter cation; and Halo is fluorine, chlorine, bromine or iodine.