Also, for the A-pPrMeOx-A, no significant difference is observed at low feed. Different from the A-pEtEtOx-A series, A-pPrMeOx-A series did not show a regularity of drug loading between each other at 6 g/L IBU feed. Similar to the situation at 8 g/L for A-pEtEtOx-A, the A-p RS PrMeOx-A shows highest LC values for R and RS-IBU. To some degree, this indicates that the solubilization of IBU is affected more by the chirality of pEtEtOx hydrophobic block than of the pPrMeOx hydrophobic block. Besides, when the IBU feed increased to 8 g/L, the copolymers containing p S EtEtOx or p S PrMeOx hydrophobic blocks showed only low drug loading. Apparently, the S-isomer "disadvantage" discussed before for S-IBU also appears in Ap S EtEtOx-A and A-p S PrMeOx-A, but we cannot rationally explain this at the moment.