Polymer Encapsulation of an Amorphous Pharmaceutical by initiated Chemical Vapor Deposition for Enhanced Stability.
Polymer Encapsulation of an Amorphous Pharmaceutical by initiated Chemical Vapor Deposition for Enhanced Stability.
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DOI：
10.1021/acsami.6b06015
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发表时间：
2016-08-24
影响因子：
9.5
通讯作者：
Werzer O
中科院分区：
文献类型：
--
作者：
Christian P;Ehmann HM;Coclite AM;Werzer O
无定形固体在实际应用中的使用，例如在药物中，通常受到这种状态的不良长期稳定性的限制，因为会发生不希望的结晶转变。在这项研究中，三种不同的聚合物涂层的稳定模型药物克霉唑的无定形膜，并防止热诱导转换的能力进行了研究。为此，克霉唑的滴铸膜通过引发的化学气相沉积（iCVD），使用丙烯酸全氟癸酯（PFDA）、甲基丙烯酸羟乙酯（HEMA）和甲基丙烯酸（MAA）来封装。iCVD技术在无溶剂的条件下在低温下操作，从而使封装层的固态不受影响。光学显微镜和X射线衍射数据显示，在约22 °C的环境条件下，这些iCVD层中的任何一个都显著延长了非晶态的寿命。在较高的温度（50或70 °C）下，p-PFDA涂层无法提供保护，而p-HEMA和p-MAA强烈降低结晶速率。此外，p-HEMA和p-MAA选择性地促进克霉唑的优先排列，并且有趣的是，甚至在暂时快速升温（3 °C/min，高达150 °C）时抑制结晶。这项研究的结果表明，聚合物涂层，直接合成的非晶相的顶部，可以作为一种稳定剂对结晶转变，这使得这种方法有趣的各种应用。
The usage of amorphous solids in practical applications, such as in medication, is commonly limited by the poor long-term stability of this state, because unwanted crystalline transitions occur. In this study, three different polymeric coatings are investigated for their ability to stabilize amorphous films of the model drug clotrimazole and to protect against thermally induced transitions. For this, drop cast films of clotrimazole are encapsulated by initiated chemical vapor deposition (iCVD), using perfluorodecyl acrylate (PFDA), hydroxyethyl methacrylate (HEMA), and methacrylic acid (MAA). The iCVD technique operates under solvent-free conditions at low temperatures, thus leaving the solid state of the encapsulated layer unaffected. Optical microscopy and X-ray diffraction data reveal that at ambient conditions of about 22 °C, any of these iCVD layers extends the lifetime of the amorphous state significantly. At higher temperatures (50 or 70 °C), the p-PFDA coating is unable to provide protection, while the p-HEMA and p-MAA strongly reduce the crystallization rate. Furthermore, p-HEMA and p-MAA selectively facilitate a preferential alignment of clotrimazole and, interestingly, even suppress crystallization upon a temporary, rapid temperature increase (3 °C/min, up to 150 °C). The results of this study demonstrate how a polymeric coating, synthesized directly on top of an amorphous phase, can act as a stabilizing agent against crystalline transitions, which makes this approach interesting for a variety of applications.