Controlled release of amorphous drug from a polymer matrix depends intimately upon the degree of mixing of drug and polymer, the susceptibility of the drug to crystallization, and the ability of the drug to dissolve and diffuse through water-swollen polymer. Characterization methods ideally would follow these processes on the molecular level in situ and in real time. We move closer to this ideal state of characterization through application of two imaging methods: digital pulsed force mode atomic force microscopy (D-PFM AFM) and confocal Raman microscopy (CRM). We examine model spin-coated films ∼1 μm thick containing the drug dexamethasone dispersed in poly(n-alkyl methacrylate) homopolymer and blend coatings. We report aqueous-immersion studies of surface and subsurface structural changes due to drug elution overtime frames ranging from very fast (a few minutes) to slow (tens of hours).
|Original language||English (US)|
|Title of host publication||Advances in Spectroscopy and Imaging of Surfaces and Nanostructures|
|Number of pages||6|
|State||Published - 2011|
|Event||2010 MRS Fall Meeting - Boston, MA, United States|
Duration: Nov 29 2010 → Dec 3 2010
|Name||Materials Research Society Symposium Proceedings|
|Other||2010 MRS Fall Meeting|
|Period||11/29/10 → 12/3/10|
Bibliographical noteFunding Information:
Support was provided by Surmodics, Inc., via its membership in the Industrial Partnership for Research in Interfacial and Materials Engineering at the University of Minnesota. Parts of this work were carried out in the University’s Characterization Facility (a Center within the College of Science and Engineering), which received partial support from the NSF through the NNIN and MRSEC programs.