Development and evaluation of a novel mucus diffusion test system approved by self-nanoemulsifying drug delivery systems.

The aim of this study was the development of a novel mucus diffusion model and the approval thereof by self-nanoemulsifying drug delivery systems (SNEDDSs). For diffusion experiments, various SNEDD formulations were developed, spiked with fluorescein diacetate, and evaluated for their mucus diffusion behavior through an intestinal mucus layer within the novel setup. In brief, SNEDD formulations resulting in particle sizes of 12.0 nm produced 70.3% of diffused model drug through the mucus layer. In comparison, SNEDDSs with particle sizes of 455.5 nm led to a permeation of 8.3% only. Apart from this size dependence, two SNEDDS excipients namely Cremophor RH 40 and triacetin were identified to strongly affect the permeation through mucus. Hence, it could be demonstrated that particle size and single excipients can positively influence mucus diffusion of SNEDDSs. Furthermore, it could be shown that the developed mucus diffusion model is a promising tool for pharmaceutical research in comparison with already established systems as it allows an easy handling coupled with the possibility to test different kinds of mucus in parallel within one setup.