The Synthesis of Mg-Zn-Al LDH and the Sustained-Release Properties of Theophylline Intercalated LDH
Layered double hydroxides (LDHs), consist of cationic brucite-like layers and exchangeable interlayer anions. In this thesis LDHs consist of brucite-like layers of zinc hydroxide, with the exchanging propertity of interlayer anions in hydrotalcites, used Mg/Zn/Al-LDH as precursor to prepare the theophylline intercalation assembly hydrotalcites to obtain supramolecular complex for the first time by co-precipitation under a nitrogen atmosphere, determined the reaction conditions and influential factors of the synthesis of theophylline-pillared hydrotalcites, and tested its sustained-release performance in different media. The product has been characterized by powder X-ray diffraction (XRD), FT-IR spectroscopy, uv-vis spectrophotometer and thermogravimetry-Differential thermal analysis (TG-DTA) . Results demonstrated that : Through co-precipitation intercalation methods, with molar ratio of Mg/Zn/Al/ theophylline being 3:1:1:2, co-precipitation medium pH9, crystallization temperature 80 °C and crystallization time 12h can obtain the clear chemical composition and good crystallization of inorganic - organic hybrid-type drugs hydrotalcites. In addition, according to Pharmacopoeia measured the release rate of theophylline-LDH in the different media including distilled water,0.9%saline,simulated intestinal fluid (pH7.4 phosphate buffer) by UV spectrophotometry, Theophylline pillared hydrotalcite has a certain release in the media above all. And calculated the release of intercalation theophylline, lay the foundation for the further clinical application.
Zhengyi Jiang, Shanqing Li, Jianmin Zeng, Xiaoping Liao and Daoguo Yang
B. Z. Du et al., "The Synthesis of Mg-Zn-Al LDH and the Sustained-Release Properties of Theophylline Intercalated LDH", Advanced Materials Research, Vols. 189-193, pp. 2448-2455, 2011