Polymer Encapsulation of an Amorphous Pharmaceutical by initiated Chemical Vapor Deposition for Enhanced Stability

• DOI: 10.1021/acsami.6b06015
• Publication Date: 2016-07-28T16:26:01Z
• Authors: Paul Christian; Heike M.A. Ehmann; Anna Maria Coclite; Oliver Werzer
• Keywords: Hot Temperature; thin film; Polymers; 01 natural sciences; molecular arrangement; clotrimazole; stabilization; X-ray diffraction; 0104 chemical sciences; iCVD; X-Ray Diffraction; encapsulation; amorphou; Gases; Crystallization

The usage of amorphous solids in practical applications, such as medication, is commonly limited by the poor long-term stability this state, because unwanted crystalline transitions occur. In study, three different polymeric coatings are investigated for their ability to stabilize films model drug clotrimazole and protect against thermally induced transitions. For this, drop cast encapsulated initiated chemical vapor deposition (iCVD), using perfluorodecyl acrylate (PFDA), hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA). iCVD technique operates under solvent-free conditions at low temperatures, thus leaving solid state layer unaffected. Optical microscopy X-ray diffraction data reveal that ambient about 22 °C, any these layers extends lifetime significantly. At higher temperatures (50 or 70 °C), p-PFDA coating unable provide protection, while p-HEMA p-MAA strongly reduce crystallization rate. Furthermore, selectively facilitate a preferential alignment and, interestingly, even suppress upon temporary, rapid temperature increase (3 °C/min, up 150 °C). results study demonstrate how coating, synthesized directly on top an phase, can act stabilizing agent transitions, which makes approach interesting variety applications.