A composition including an association complex of a pharmaceutical composition and one or more polyethylene-polypropylene glycol block copolymers (poloxamers) is provided. The pharmaceutical composition may include a member selected from the group consisting of (a) an association complex of an eprosartan composition including eprosartan or a pharmaceutically acceptable salt of eprosartan and (b) the non-zwitterionic compound 2-(7-chloro-S-methyl-4-oxo-3-phenyl-4,S dihydro-3H-pyridazino (4,S-b)indol-1-yl)N, N-dimethylacetamide (NZ).
