Development and evaluation of a new gastroretentive drug delivery system: Nanomicelles-loaded floating mucoadhesive beads

To better treat gastric diseases and lower systemic side effect, it is essential to design new vectors to control drug release in stomach. Aiming to this challenge, we developed a new gastroretentive drug delivery system : nanomicelles-loaded gastroretentive beads. Firstly, the chitosan-coated emodin-loaded nanomicelles were developed and characterized. In vitro cytotoxicity of emodin-loaded nanomicelles, emodin suspensions and blank nanomicelles was evaluated with human gastric carcinoma SGC-7901 cells by MTT , indicating that the blank nanomicelles had null cytotoxicity and emodin-loaded nanomicelles had better antitumor efficacy compared with emodin suspensions. Secondly, nanomicelles-loaded floating mucoadhesive beads (NFM-Beads) were prepared, and the swelling, degradation, mucoadhesion and floating ability in vitro were separately investigated. FT-IR spectroscopy was applied to identify the formation of nanomicelles and NFM-Beads. Emodin release from NFM-Beads in vitro was fitted to anomalous transport mechanism. In vivo gastroretention behavior of NFM-Beads was evaluated by BaSO 4 -based X-ray imaging exams, showing that NFM-Beads can be retained in rabbit stomach for at least 8 h. Overall, the new NFM-Beads system could be an effective approach to improve the therapeutic potency of drug against gastric cancer.