Double-wall microspheres (DWMS), comprising distinct polymer core and shell phases, are useful and interesting for controlled-release drug delivery. In particular, the presence of a surface-eroding polymer core may be expected to limit water penetration and, therefore, delay degradation of the core phase and drug release. In this study, solid microspheres and DWMS were fabricated using a surface-eroding polymer (poly[1,6-bis(p-carboxyphenoxy)hexane]; PCPH) and a bulk-eroding polymer (poly(d,l-lactide-co-glycolide); PLG). Erosion of the particles was observed by optical and electron microscopy, while polymer degradation was followed by gel permeation chromatography, during incubation in buffer at 37°C. Degradation and erosion were very different depending on which polymer formed the particle shell. Nevertheless, the relatively thin (∼5 μm) PCPH shells could not prevent water penetration, and the PLG cores completely eroded by 6 weeks of incubation.
|Number of pages||10|
|Journal||International Journal of Pharmaceutics|
|State||Published - Sep 14 2005|
Bibliographical noteFunding Information:
This work was partly supported by NIH grant EB002878. The synthesis of PCPH by Matt Kipper and Balaji Narasimhan at Iowa State University is gratefully acknowledged. Scanning electron microscopy was carried out at the Center for Microanalysis of Materials, University of Illinois at Urbana-Champaign, which is partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439.
- Double-wall microsphere
ASJC Scopus subject areas
- Pharmaceutical Science