A large proportion of new drugs and drug candidates exhibit very low water solubility. This poses a significant challenge to the pharmaceutical industry and a variety of different formulation strategies are employed to overcome this solubility challenge. The amorphous form with its disordered structure has a higher free energy (in lieu of the lattice stabilization) compared to the crystalline form, resulting in a higher apparent solubility, dissolution rate and potentially oral absorption of the drug. Due to the thermodynamically favorable transition towards the lower energy crystalline state rendering the amorphous form physically unstable, pure amorphous drug forms are rarely used on their own. Addition of an excipient (usually a polymer) to form an amorphous solid dispersion can stabilize the drug against crystallization during both processing and storage. Often, the added polymer inhibits recrystallization through, inter alia, reducing the molecular mobility of the drug and/or forming hydrogen bonds with the drug in a single phase system with molecular mixing of the components. Furthermore, the excipient can modulate the dissolution profile of the drug and inhibit crystallization after dissolution. Depending on the properties of the drug and polymer, different methods can be used for the preparation of ASDs, with hot melt extrusion (HME) and spray drying being the most important and widely used processes in industry. HME is a continuous and single-step process, which does not require the use of any solvent and is therefore considered more sustainable compared to spray drying. It involves the mixing and melting of the excipient and drug with subsequent extrusion. Well-known and studied polymers for HME and used in multiple commercial products are, inter alia, hydroxypropyl methylcellulose (HPMC) , HPMC derivates , poly(vinyl pyrrolidone) (PVP) and poly(vinyl pyrrolidone-co-vinyl acetate) (P(VP-co-VA)) . Apart from these wellestablished polymers, Soluplus® has been introduced specifically for HME and other experimental excipients, such as poly(2-ethyl-2-oxazoline) and ABA triblock copolymers comprising poly(2-oxazoline) (POx) and poly(2-oxazine) (POzi) moieties, have been studied for HME more recently. Interestingly, PVP and P(VP-co-VA), are structurally similar to Soluplus® and POx/POzi based polymers, in that they all contain tertiary amide groups in their repeating units, which may act as hydrogen bond acceptors (but not H-donors) for the drug. However, unlike PVP and P(VP-co-VA), the POx/POzi based amphiphilic ABA triblock copolymers form well-defined micelles in aqueous solution. Previously, the latter have been explored in high drug loading polymeric nanoformulations with drug loadings of more than 50wt% , as well as stabilization of drug nano-and microparticles . In the springand-parachute model often described for ASDs, the ASD serves as the spring, while the in situ formed micelles serve as a parachute by increasing the apparent aqueous solubility of the drug. The drug loaded micelles can remain colloidally stable over a period of up to several months, as previously shown for a variety of drugs with the POx/POzi platform. In particular, polymers containing poly(2-methyl-2-oxazoline) (pMeOx) as the A block and poly(2-butyl-2oxazoline) (pBuOx) and poly(2-butyl-2-oxazine) (pBuOzi), as the B block, have been used successfully in high drug loading micellar formulations , stabilization of drug nanocrystals and drug loaded microneedles . It should be noted that, for some POx/POzi systems, a reasonably good drug loading capacity (albeit lower than for triblocks) can be achieved by changing the polymer structure to diblock, random or gradient copolymers. In this study, the amphiphilic ABA triblock copolymers pMeOx-pBuOzi-pMeOx and pMeOx-pBuOx-pMeOx were investigated as excipients for the preparation of ASDs with indomethacin (IND) as a model drug in different drug loadings, ranging from 25wt% to 80wt% and HME as an industrially relevant processing method. IND is often used as a model drug for the development of ASDs. The goal of this study is to compare the performance of the POx and POzi based polymers to the industrially used PVP and P(VP-co-VA) as crystallization inhibiting excipients in ASDs at very high drug loadings. To do so, the prepared extrudates were analyzed by DSC, PXRD and solid-state NMR measurements. Furthermore, the dissolution behavior as a function of both polymers and drug loading was evaluated.