Fernández-Pérez M, Villafranca-Sánchez M, Flores-Céspedes F
Department of Inorganic Chemistry, University of Almería, Almería, Spain.
J Environ Sci Health B. 2007 Sep-Oct;42(7):863-8. doi: 10.1080/03601230701555153.
An encapsulation system was developed and designed to give long-lasting effectiveness of the insect growth regulator cyromazine. Cyromazine was incorporated in lignin-poly (ethylene glycol) (PE) controlled-release formulations by means of a melting process. The basic formulation [lignin (65%)-PE (20%)-cyromazine (15%)] was coated in a Wurster-type fluidized-bed equipment using two different amounts of ethylcellulose. That of the highest one was modified by the addition of a plasticizer, dibutyl sebacate (DBS). The effect on cyromazine release rate caused by the incorporation of ethylcellulose and DBS in lignin-PE formulation was studied by immersion of the granules in water under static conditions. Using an empirical equation, the time taken for 50% of the active ingredient to be released into water (T(50)) was calculated. From the analysis of the T(50) values, the influence of ethylcellulose appears clearly defined, observing a delay in release rate of cyromazine with respect to the basic lignin-PE formulation. In addition, the granules coated with ethylcellulose and the plasticizer lead the slowest release rate into water. The release of cyromazine into water is controlled by a diffusion mechanism. The thickness and permeability of the coating film are the most important factors that affect cyromazine release.
开发并设计了一种包封系统，以使昆虫生长调节剂环丙氨嗪具有长效效果。通过熔融工艺将环丙氨嗪掺入木质素 - 聚乙二醇（PE）控释制剂中。基本配方[木质素（65%）-PE（20%）-环丙氨嗪（15%）]在Wurster型流化床设备中使用两种不同量的乙基纤维素进行包衣。其中用量最高的配方通过添加增塑剂癸二酸二丁酯（DBS）进行了改性。通过在静态条件下将颗粒浸入水中，研究了在木质素 - PE配方中加入乙基纤维素和DBS对环丙氨嗪释放速率的影响。使用经验方程计算活性成分50%释放到水中所需的时间（T(50)）。通过对T(50)值的分析，乙基纤维素的影响清晰可见，相对于基本的木质素 - PE配方，环丙氨嗪的释放速率出现延迟。此外，涂有乙基纤维素和增塑剂的颗粒在水中的释放速率最慢。环丙氨嗪在水中的释放受扩散机制控制。包衣膜的厚度和渗透性是影响环丙氨嗪释放的最重要因素。
