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以中链甘油三酯(MCT)为油相,α-环糊精(α-CD)为主要辅料制备了MCT乳剂,考察乳剂的形成机制。通过界面张力和接触角的测定,并采用粉末X-射线衍射、扫描电镜、高效液相色谱法、微分干涉显微镜和冷冻扫描电镜对MCT/α-CD固体微粒进行表征。通过测定不同含量α-CD的乳剂粒径与沉降体积比,并采用倒置相差显微镜观察乳滴形态,对乳剂的物理稳定性进行考察。结果表明,α-CD分子与MCT在油/水界面自组装形成了两亲性超分子,导致油/水界面张力降低;两亲性超分子进而形成固体微粒,并吸附于油/水界面,形成膜结构,使乳剂系统稳定。MCT/α-CD固体微粒的接触角为(46.1±3.4)°,小于90°。乳剂连续相中的α-CD含量越高,油/水界面以及连续相中生成的固体微粒量越多,乳滴粒径越小,连续相的黏度越大。因此,α-CD/MCT/水乳剂是一种O/W型的Pickering乳,乳剂连续相中α-CD含量越高,乳剂的物理稳定性越好。
The MCT emulsion was prepared with medium-chain triglyceride (MCT) as the oil phase and α-cyclodextrin (α-CD) as the main excipients to investigate the formation mechanism of the emulsion. The MCT / α-CD solid particles were characterized by means of determination of interfacial tension and contact angle, powder X-ray diffraction, scanning electron microscopy, high performance liquid chromatography, differential interference microscopy and cryo-scanning electron microscopy. By measuring the particle size and sedimentation volume ratio of different content of α-CD emulsion, and observing the droplet morphology by inverted phase contrast microscope, the physical stability of the emulsion was investigated. The results showed that the α-CD molecules self-assembled with MCT at the oil / water interface to form amphiphilic supramolecules, resulting in the decrease of oil / water interfacial tension. The amphiphilic supramolecules then formed solid particles and adsorbed on the oil / water interface, Form a membrane structure that stabilizes the emulsion system. The contact angle of MCT / α-CD solid particles was (46.1 ± 3.4) °, less than 90 °. The higher the alpha-CD content in the emulsion continuous phase, the greater the amount of solid particles formed at the oil / water interface and in the continuous phase and the smaller the droplet size, the greater the viscosity of the continuous phase. Therefore, the α-CD / MCT / water emulsion is an O / W Pickering emulsion, the higher the α-CD content in the emulsion continuous phase, the better the physical stability of the emulsion.