Department of Drug Chemistry and Technologies, “Sapienza”, University of Rome, Italy.
J Pharm Pharm Sci. 2011;14(3):336-46. doi: 10.18433/j3160b.
PURPOSE. Aim of this research was to prepare and study drug release from a new formulation consisting of non ionic surfactant vesicular structures, niosomes (NSVs), loaded with model molecules calcein (CALC), nile red (NR), ibuprofen (IBU) or caffeine (CAFF), and embedded in a hydrogel matrix. METHODS. The system locust bean gum/xanthan (1:1), prepared at 60 °C, was used to entrap the vesicles (Tween 20/cholesterol 1:1), loaded with guest molecules and the release profiles were detected at 32 °C. The hydrogel systems were characterized by means of scanning electron microscopy; niosomes were characterized by means of size and -potential measurements. RESULTS. Size measurements showed that a slight increase in vesicle dimensions occurs after inclusion of CALC or CAFF (hydrophilic molecules) in the vesicular structures. -potential measurements showed that the inclusion of these molecules did not significantly modify the surface charge of empty vesicles. This was probably related to an almost negligible drug adsorption on the vesicle surface. The release from the niosomes-gel systems of two probes (CALC and NR) showed that the diffusion of CALC through the gel was not affected by the niosome entrapment while for NR, the presence of vesicles was crucial. The release profiles from niosomes-gel systems and from the hydrogel alone of model drugs, CAFF and IBU, showed an appreciable difference between the two drugs: the more hydrophilic CAFF was released much faster than IBU. In all release studies turbidity, dimension and -potential analyses indicated that the loaded niosomes were released by the hydrogel matrix without being damaged. CONCLUSIONS. The reported in vitro experiments show the capability of the novel formulation to combine the qualities of both chosen single systems, i.e. the niosomes and the polymeric network. The hydrogel shows a protective effect on vesicle integrity and leads to a slow release of the loaded model molecules from the polysaccharidic system. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.
目的。本研究的目的是制备和研究由非离子表面活性剂囊泡结构、囊泡（NSVs）组成的新制剂，该制剂负载模型分子钙黄绿素（CALC）、尼罗红（NR）、布洛芬（IBU）或咖啡因（CAFF），并嵌入水凝胶基质中。方法。在 60°C 下制备角叉菜胶/黄原胶（1:1）系统，用于包封负载客体分子的囊泡（吐温 20/胆固醇 1:1），并在 32°C 下检测释放曲线。通过扫描电子显微镜对水凝胶系统进行了表征；通过粒径和 ζ-电位测量对囊泡进行了表征。结果。粒径测量表明，CALC 或 CAFF（亲水分子）被包封在囊泡结构中后，囊泡尺寸略有增加。ζ-电位测量表明，这些分子的加入并没有显著改变空囊泡的表面电荷。这可能与药物在囊泡表面的吸附可忽略不计有关。两种探针（CALC 和 NR）从囊泡-凝胶系统中的释放表明，CALC 通过凝胶的扩散不受囊泡包封的影响，而对于 NR，囊泡的存在至关重要。模型药物 CAFF 和 IBU 从囊泡-凝胶系统和单独水凝胶的释放曲线表明，两种药物之间存在明显差异：亲水性更强的 CAFF 释放速度比 IBU 快得多。在所有释放研究中，浊度、尺寸和 ζ-电位分析表明，负载的囊泡在不被破坏的情况下被水凝胶基质释放。结论。本报告的体外实验表明，新型制剂具有结合所选两种单一系统（即囊泡和聚合网络）优点的能力。水凝胶对囊泡完整性具有保护作用，并导致从多糖系统中缓慢释放负载的模型分子。本文接受发表后评审。注册读者（见“读者须知”）可点击问题内容页面上的摘要进行评论。
