Assessing the performance of thermally crosslinked amorphous solid dispersions with high drug loadings

Continuing what previous studies had also intended, the present study aims to shed light on some unanswered questions concerning a recently introduced class of high drug loading (HD) amorphous solid dispersions (ASDs), based on the in-situ thermal crosslinking of poly (acrylic acid) (PAA) and poly (vinyl alcohols) (PVA). Initially, the effect of supersaturated dissolution conditions on the kinetic solubility profiles of the crosslinked HD ASDSs having indomethacin (IND) as a model drug, was determined. Subsequently, the safety profile of these new crosslinked formulations was determined for the first time by evaluating their cytotoxic effect on human intestinal epithelia cell line (Caco-2), while their ex-vivo intestinal permeability was also studied via the non-everted gut sac method. According to the obtained findings, the in-situ thermal crosslinked IND HD ASDs present similar kinetic solubility profiles when the dissolution studies are conducted with a steady sink index value, regardless of the different dissolution medium's volume and the total dose of the API. Additionally, the results showed a concentration- and time- dependent cytotoxicity profile for all formulations, while the neat crosslinked PAA/PVA matrices did not elicit cytotoxicity during the first 24 h, even at the highest examined concentration. Finally, the newly proposed HD ASD system, resulted in a remarkably increased ex-vivo intestinal permeability of IND.