Interestingly, both A-pEtEtOx-A and A-pPrMeOx-A series have a similar and relatively high IBU LC exceeding 30 wt %. In terms of maximum IBU LC of A-pEtEtOx-A series formulations, the highest LC is Ap R EtEtOx-A/R-IBU (37 wt %), the lowest LC is A-p RS EtEtOx-A/S-IBU (32 wt %). The formulation in the A-pPrMeOx-A series with highest LC is A-p RS PrMeOx-A/R-IBU (36 wt %), the lowest LC values are observed for A-p R PrMeOx-A/RS-IBU and M A-pPrMeOx-A/S-IBU (31 wt %). The maximum LC of the rest formulations vary within these limits without any notable regularity. In contrast to CUR or PTX, there is no clear and significant difference for IBU solubilization between the A-pEtEtOx-A and A-pPrMeOx-A series, even though overall the A-pEtEtOx-A series seems to have somewhat higher LC values. In order to view the LC of different IBUs loaded in one of our triblock copolymers, the LC data was arranged in one coordinate system (Fig. ). Up to 6 g/L IBU feed no significant differences were observed between R, S and RS-IBU for any triblock copolymer. At 8 g/L, the LC values for R-IBU and RS-IBU are similar for the same triblock copolymer, but the LC values of S-IBU trails behind for several polymers, especially in A-p RS EtEtOx-A and A-p RS PrMeOx-A. Coincidentally, the copolymer A-p RS EtEtOx-A (Fig. ) and A-p RS PrMeOx-A (Fig. Besides, formulations for the different A-pEtEtOx-A (Fig. ) or A-pPrMeOx-A formulations (Fig. ) with different IBUs are compared. Again, up to 4 g/L drug feed, no real difference was observed. However, with increasing IBU feed to 6 g/L, the drug loading of A-p RS EtEtOx-A was always lowest while drug loading for A-p R EtEtOx-A was highest in all three cases (Fig. ). The drug loading for M A-pEtEtOx-A and Ap S EtEtOx-A were basically the same and intermediate. At 8 g/L the picture looks much different, with the A-p RS EtEtOx-A showing highest LC values for R and RS-IBU.