In the case of POx/POzi based formulations, it is becoming more evident that the after a certain threshold drug feed, the hydrophilic corona start to interact with the hydrophobic drug and this association may lead to high drug loading and/or eventually the formulation agglomeration and precipitation. In majority cases, the drug was found to be amorphous in these agglomerate/precipitates with the exception of A-pBuOx-A/MT formulation where at 6 g/L MT feed, the rapid crystallization of drug was observed. The differential scanning calorimetry (DSC) measurement further confirmed the presence of crystalline mitotane. Herein, for MT formulations, we can also speculate the similar phenomena, particularly for A-pBuOzi-A triblock based formulations, where a rapid formulation instability can be observed even at lower MT feed i.e. 4 g/L (Figure ). While, the poor instability in the case of the A-pPentOx-A triblock copolymer might hint towards different mechanism, as we have observed this poor stability problem in most of the other drug presented herein.