Bouchemal K, Briançon S, Couenne F, Fessi H, Tayakout M
Laboratoire d'Automatique et de Génie des Procédés, UMR-CNRS 50 07 CPE Lyon, Université Claude Bernard Lyon 1, 43, Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France.
J Nanosci Nanotechnol. 2006 Sep-Oct;6(9-10):3187-92. doi: 10.1166/jnn.2006.468.
Generally nanocapsules suspensions are a colloidal system in a metastable state, there is aggregation due to attraction and repulsion forces between particles. The objective of this work was to bring the role of the polymeric membrane in the protection of the active drug against damaging caused by external agents and to select the monomer which leads to obtain stable formulation with the highest possible payload of the active drug. The stability testing involving visual aspect, particle size measurement, transmission electron microscopy (TEM) examination, and drug loss was conduced after 6 months of storage at different temperatures (4, 25, and 45 degrees C). The colloidal suspensions of nanocapsules were obtained using the combined interfacial polycondensation and spontaneous emulsification, the technique was used to encapsulate alpha-tocopherol using polyurethanes polymers. It is a one step procedure: An organic phase composed of a water miscible solvent (acetone), lipophilic monomer (Isophorone diisocyanate IPDI), oil, and a lipophilic surfactant, is injected in an aqueous phase containing hydrophilic monomer (diol with various molecular weight: 1,2-ethanediol (ED), 1,4-butanediol (BD), and 1,6-hexanediol (HD)) and hydrophilic emulsifying agent. The water miscible solvent diffuses to the aqueous phase, the oil precipitates as nano-droplets, and the two monomers react at the interface, forming a membrane around the nanoemulsion leading to nanocapsules. A good physical stability of suspensions corresponds to absence of symptoms such as sedimentation or agglomeration, significant size change and alpha-tocopherol degradation due to external agents such as oxygen, temperature, and ultraviolet (UV) irradiation. The size of nanocapsules before storage was about 232 +/- 3, 258 +/- 29, and 312 +/- 4 nm for ED, BD, and HD, respectively. After 6 months of storage, polyurethanes nanocapsules possess good stability against aggregation at 4 and 25 degrees C. Comparing results obtained using different monomers, it reveals that the polyurethane based on HD offers good protection of alpha-tocopherol against damaging caused by the temperature and UV irradiation.
一般来说，纳米胶囊悬浮液是一种处于亚稳态的胶体系统，由于颗粒间的吸引力和排斥力会发生聚集。这项工作的目的是探究聚合物膜在保护活性药物免受外部因素损害方面的作用，并选择能得到具有最高活性药物载药量的稳定制剂的单体。在不同温度（4℃、25℃和45℃）下储存6个月后，进行了包括外观、粒径测量、透射电子显微镜（TEM）检查和药物损失在内的稳定性测试。纳米胶囊的胶体悬浮液是通过界面缩聚和自发乳化相结合的方法制备的，该技术用于用聚氨酯聚合物包裹α-生育酚。这是一个一步法过程：将由与水混溶的溶剂（丙酮）、亲脂性单体（异佛尔酮二异氰酸酯IPDI）、油和亲脂性表面活性剂组成的有机相注入含有亲水性单体（不同分子量的二醇：1,2-乙二醇（ED）、1,4-丁二醇（BD）和
1,6-己二醇（HD））和亲水性乳化剂的水相中。与水混溶的溶剂扩散到水相中，油沉淀为纳米液滴，两种单体在界面处反应，在纳米乳液周围形成一层膜，从而得到纳米胶囊。悬浮液良好的物理稳定性表现为没有诸如沉降或团聚、显著的尺寸变化以及由于氧气、温度和紫外线（UV）照射等外部因素导致的α-生育酚降解等症状。储存前，ED、BD和HD纳米胶囊的粒径分别约为232±3、258±29和312±4 nm。储存6个月后，聚氨酯纳米胶囊在4℃和25℃下具有良好的抗聚集稳定性。比较使用不同单体获得的结果表明，基于HD的聚氨酯对α-生育酚具有良好的保护作用，可使其免受温度和紫外线照射的损害。
