caa a22 4500 477125867 CHVBK 20180405111649.0 cr unu---uuuuu 170330e19970601xx s 000 0 eng 10.1023/A:1012123127330 doi (NATIONALLICENCE)springer-10.1023/A:1012123127330 In Vitro/In Vivo Comparison of Drug Release and Polymer Erosion from Biodegradable P(FAD-SA) Polyanhydrides—A Noninvasive Approach by the Combined Use of Electron Paramagnetic Resonance Spectroscopy and Nuclear Magnetic Resonance Imaging [Elektronische Daten] [Karsten Mäder, Yannick Crémmilleux, Abraham Domb, Jeffrey Dunn, Harold Swartz] Purpose. The purpose of this study was to compare drug release and polymer erosion from biodegradable P(FAD-SA) polyanhydrides in vitro and in vivoin real time and with minimal disturbance of the investigated system. Methods. P(FAD-SA) 20:80 and P(FAD-SA) 50:50 polymer tablets were loaded with the spin probe 3-carboxy-2,2,5,5-tetramethyl-pyrrollidine-1-oxyl (PCA) and implanted subcutaneously in the neck of rats or placed in 0.1 M phosphate buffer. 1.1 GHz EPR spectroscopy experiments and 7T MRI studies (Tl and T2 weighted) were performed. Results. A front of water penetration was visible by MRI in vitro in the case of P(FAD-SA) 20:80, but not for P(FAD-SA) 50:50. For both polymers, the thickness of the tablets decreased with time and a insoluble, easy deformable residue remained. Important processes such as edema, deformation of the implant, encapsulation and bioresorption were observable by MRIin vivo. P(FAD-SA) 50:50 was almost entirely absorbed by day 44, whereas an encapsulated residue was found for P(FAD-SA) 20:80 after 65 days. The EPR studies gave direct evidence of a water penetration induced changes of the microenvironment inside the tablet. EPR signals were still detectable in P(FAD-SA) 20:80 implants after 65 days, while the nitroxide was released in vitro within 16 days. Conclusions. Important parameters and processes such as edema, deformation of the tablet, micro viscosity inside the tablet and encapsulation can be monitored in real time by the combined use of the noninvasive techniques MRI and EPR leading to better understanding of the differences between the in vitroandin vivo situation. Plenum Publishing Corporation, 1997 biodegradable polymers nationallicence EPR nationallicence MRI nationallicence drug delivery nationallicence in vitro/in vivo correlation nationallicence Mäder Karsten Institute of Pharmacy Humboldt-University Berlin, Goethestr. 54, 13086, Berlin, Germany aut Crémmilleux Yannick Laboratoire de RMN, CPE, Universite Claude Bernard, Villeurbanne Cedex, France aut Domb Abraham School of Pharmacy, The Hebrew University Jerusalem, 91120, Jerusalem, Israel aut Dunn Jeffrey Dept. of Radiology, Dartmouth Medical School, 03755, Hanover, New Hampshire, USA aut Swartz Harold Dept. of Radiology, Dartmouth Medical School, 03755, Hanover, New Hampshire, USA aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/6(1997-06-01), 820-826 0724-8741 14:6<820 1997 14 11095 https://doi.org/10.1023/A:1012123127330 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012123127330 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mäder Karsten Institute of Pharmacy Humboldt-University Berlin, Goethestr. 54, 13086, Berlin, Germany aut NATIONALLICENCE 700 1- Crémmilleux Yannick Laboratoire de RMN, CPE, Universite Claude Bernard, Villeurbanne Cedex, France aut NATIONALLICENCE 700 1- Domb Abraham School of Pharmacy, The Hebrew University Jerusalem, 91120, Jerusalem, Israel aut NATIONALLICENCE 700 1- Dunn Jeffrey Dept. of Radiology, Dartmouth Medical School, 03755, Hanover, New Hampshire, USA aut NATIONALLICENCE 700 1- Swartz Harold Dept. of Radiology, Dartmouth Medical School, 03755, Hanover, New Hampshire, USA aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/6(1997-06-01), 820-826 0724-8741 14:6<820 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer