Provided herein in some embodiments are pharmaceutical compositions comprising a prostacyclin (PGI2) receptor agonist selected from 2-(((1r,4r)-4-(((4-chlorophenyl)(phenyl)carbamoyloxy)methyl)cyclohexyl)methoxy)acetic acid (Compound 1) and pharmaceutically acceptable salts, solvates, and hydrates thereof, as disclosed herein. In some embodiments the pharmaceutical compositions comprise a compound selected from 2-(((1r,4r)-4-(((4-chlorophenyl)(phenyl)carbamoyloxy)methyl)cyclohexyl)methoxy) acetic acid (Compound 1), and pharmaceutically acceptable salts, solvates, and hydrates thereof, in an amount equivalent to a therapeutically effective amount of Compound 1, the composition having a release rate by weight of the compound in an aqueous medium that is one or more of release rates (a), (b) and (c) as disclosed herein. The compositions of the present invention are useful in the treatment of PGI2 related disorders, such as those disclosed herein.