The effects of surfactants on the performance of polymer-based microwave-induced in situ amorphization

Microwave-induced in situ amorphization is a novel technology for preparing amorphous solid dispersions (ASDs) to address the challenges of their long-term physical stability and downstream processing. To date, only few types of dielectric materials have been reported for microwave-induced in situ amorphization, which restricted the extensive research of this technology. This study aimed to investigate the feasibility and mechanisms of utilizing the non-ionic surfactants, i.e. Kollisolv P124, Kolliphor RH40, D-ɑ-tocopheryl polyethylene glycol succinate (TPGS), Tween 60 (T60), T65, T80 and T85, as plasticizers to facilitate microwave-induced in situ amorphization. It was found that the successful application of surfactants could be related with their low T_m, low M_w and high HLB. Kolliphor RH40 was selected as a typical surfactant due to its excellent dielectric heating ability, plasticizing effect and solubilizing effect when facilitating amorphization.

Then, the dissolution-mediated in situ amorphization mechanism was investigated and intuitively demonstrated. For the most promising formulation, i.e. microwaved systems with Kolliphor RH40 at 1.5 (w/w) plasticizer/polymer ratio, a complete and fast in vitro dissolution was observed relative to the untreated systems. In conclusion, non-ionic surfactants had the potential to facilitate microwave-induced in situ amorphization, which provided a new direction in the formulation designation for microwave-able systems.

Wei Qiang, Korbinian Löbmann, Colin P. McCoy, Gavin P. Andrews, Min Zhao, The effects of surfactants on the performance of polymer-based microwave-induced in situ amorphization, International Journal of Pharmaceutics,
2022, 122426, ISSN 0378-5173, https://doi.org/10.1016/j.ijpharm.2022.122426.

See also the interesting video on Vitamin E TPGS: