负载旋覆代赭汤的白及多糖胃漂浮剂的制备、表征及其胃肠道滞留性能评价

Preparation, characterization and gastrointestinal retention evaluation of a Bletilla striata polysaccharide gastric floating formulation loaded with Xuanfu Daizhe Tang

关键词:  旋覆代赭汤  白及多糖  胃食管反流病  胃肠道滞留  胃漂浮剂

Key words:  Xuanfu Daizhe Tang  Bletilla striata polysaccharide  gastroesophageal reflux disease  gastrointestinal retention  gastric floating agent

摘要:

目的 针对胃食管反流病，制备负载旋覆代赭汤提取物（XDT-P）的白及多糖胃漂浮剂（XDT@BSP-FS），并评价其漂浮与滞留性能。方法 通过混合溶胀法制备白及多糖（BSP）-油酸甘油酯（GMO）水凝胶骨架（BSP-FS），负载XDT-P得到XDT@BSP-FS，对其漂浮性能、微观结构、理化表征、流变与力学特性、体外消化及在体滞留性能进行系统评价。结果 XDT@BSP-FS可在0 s内快速起漂，形成的浮层厚度为0.52 cm，漂浮可稳定维持 > 8 h。结构表征显示XDT@BSP-FS内部形成致密层状多孔网络，热分析（DSC）与红外（FT-IR）结果显示XDT-P在BSP-FS骨架中以物理结合形式存在。相同剂量XDT@BSP-FS表现出优于市售药物Gaviscon^®的韧性。体内外荧光成像结果显示，XDT@BSP-FS灌胃后于活体成像中胃肠道荧光信号可持续 > 4 h，离体成像中至6 h仍可检测到明显荧光信号，而吲哚菁绿（ICG）水溶液组荧光信号于4 h时已明显减弱。结论 XDT@BSP-FS具备快速起漂、长效漂浮与良好的体内滞留性能，可为胃食管反流相关疾病的胃滞留给药系统研究提供参考。

Abstract:

Objective To prepare a Bletilla striata polysaccharide gastric floating agent loaded with Xuanfu Daizhe Tang extract (XDT@BSP-FS) for gastroesophageal reflux induced nausea and vomiting, and to evaluate its floating and gastric retention properties. Methods A Bletilla striata polysaccharide (BSP) -glyceryl monooleate (GMO) hydrogel framework (BSP-FS) was prepared via a mixed swelling method, followed by loading with Xuanfu Daizhe Tang to yield XDT@BSP-FS. The floating performance, microstructure, physicochemical properties, rheological and mechanical properties, in vitro digestion behavior, and in vivo retention behavior were systematically evaluated. Results XDT@BSP-FS exhibited immediate floating (0 s), formed a floating layer with a thickness of 0.52 cm, and maintained stable buoyancy for over 8 h. Structural characterization revealed the formation of a dense, lamellar porous network within XDT@BSP-FS. Thermal analysis (DSC) and Fourier transform infrared spectroscopy (FT-IR) indicated that Xuanfu Daizhe Tang existed within the BSP-FS framework predominantly through physical interactions. At equivalent doses, XDT@BSP-FS demonstrated superior mechanical toughness compared with the commercially available product Gaviscon^®. In vivo and ex vivo fluorescence imaging demonstrated that, following intragastric administration of XDT@BSP-FS, the gastrointestinal fluorescence signal persisted for more than 4 h in vivo, and obvious fluorescence was still detectable at 6 h ex vivo. By contrast, the fluorescence signal in the indocyanine green (ICG) aqueous solution group was already markedly attenuated at 4 h. Conclusion XDT@BSP-FS exhibited rapid flotation, prolonged floating duration, and favorable in vivo retention behavior, providing a reference for the development of gastroretentive drug delivery systems for gastroesophageal reflux related diseases.