Chulalongkorn University, Bangkok 10330, Thailand.
Int J Pharm. 2010 May 31;391(1-2):267-73. doi: 10.1016/j.ijpharm.2010.02.020. Epub 2010 Feb 17.
The six fragrances, camphor, citronellal, eucalyptol, limonene, menthol and 4-tert-butylcyclohexyl acetate, which represent different chemical functionalities, were encapsulated with a polymer-blend of ethylcellulose (EC), hydroxypropyl methylcellulose (HPMC) and poly(vinyl alcohol) (PV(OH)) using solvent displacement (ethanol displaced by water). The process gave >or=40% fragrance loading capacity with >or=80% encapsulation efficiency at the fragrance to polymer weight ratio of 1:1 and at initial polymer concentrations of 2000-16,000 ppm and the obtained fragrance-encapsulated spheres showed hydrodynamic diameters of less than 450 nm. The release profile of the encapsulated fragrances, evaluated by both thermal gravimetric and electronic nose techniques, indicated different release characteristics amongst the six encapsulated fragrances. Limonene showed the fastest release with essentially no retention by the nanoparticles, while eucalyptol and menthol showed the slowest release.
六种香料，包括樟脑、香茅醛、桉油醇、柠檬烯、薄荷醇和 4-叔丁基环己基乙酸酯，分别代表不同的化学功能，通过溶剂置换（乙醇被水置换）的方法，用乙基纤维素（EC）、羟丙基甲基纤维素（HPMC）和聚乙烯醇（PV（OH））的聚合物共混物进行包封。在香料与聚合物的重量比为 1:1 且初始聚合物浓度为 2000-16,000ppm 的情况下，该过程可使香料的负载能力达到>or=40%，包封效率达到>or=80%，所得的香料包封球的水动力直径小于 450nm。通过热重分析和电子鼻技术评估包封香料的释放情况，表明六种包封香料之间具有不同的释放特性。柠檬烯显示出最快的释放速度，基本上没有被纳米颗粒保留，而桉油醇和薄荷醇显示出最慢的释放速度。
