Ribeiro C, Arizaga G G C, Wypych F, Sierakowski M-R
Laboratório de Biopolímeros, Departamento de Química, Universidade Federal do Paraná, C.P. 19081, 81531-980 Curitiba, Paraná, Brazil.
Int J Pharm. 2009 Feb 9;367(1-2):204-10. doi: 10.1016/j.ijpharm.2008.09.037. Epub 2008 Sep 30.
Enalaprilate (Enal), an active pharmaceutical component, was intercalated into a layered double hydroxide (Mg/Al-LDH) by an ion exchange reaction. The use of a layered double hydroxide (LDH) to release active drugs is limited by the low pH of the stomach (pH approximately 1.2), in whose condition it is readily dissolved. To overcome this limitation, xyloglucan (XG) extracted from Hymenaea courbaril (jatobá) seeds, Brazilian species, was used to protect the LDH and allow the drug to pass through the gastrointestinal tract. All the materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, elemental analyses, transmission electronic microscopy, thermal analyses, and a kinetic study of the in vitro release was monitored by ultraviolet spectroscopy. The resulting hybrid system containing HDL-Enal-XG(3) slowly released the Enal. In an 8-h of test, the system protected 40% (w/v) of the drug. The kinetic profile showed that the drug release was a co-effect behavior, involving dissolution of inorganic material and ion exchange between the intercalated anions in the lamella and those of phosphate in the buffer solution. The nanocomposite coated protection with XG was therefore efficient in obtaining a slow release of Enal.
依那普利拉（Enal）作为一种活性药物成分，通过离子交换反应插层到层状双氢氧化物（Mg/Al-LDH）中。使用层状双氢氧化物（LDH）释放活性药物受到胃低pH值（约为1.2）的限制，在此条件下它很容易溶解。为克服这一限制，从巴西物种孪叶豆种子中提取的木葡聚糖（XG）被用于保护LDH，并使药物能够通过胃肠道。所有材料均通过X射线衍射、傅里叶变换红外光谱、元素分析、透射电子显微镜、热分析进行表征，体外释放的动力学研究通过紫外光谱进行监测。所得的包含HDL-Enal-XG(3)的杂化体系缓慢释放依那普利拉。在8小时的测试中，该体系保护了40%（w/v）的药物。动力学曲线表明，药物释放是一种协同效应行为，涉及无机材料的溶解以及层间插层阴离子与缓冲溶液中磷酸根离子之间的离子交换。因此，用XG包覆的纳米复合材料保护在实现依那普利拉的缓慢释放方面是有效的。
