caa a22 4500 445313005 CHVBK 20180317142636.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s11095-011-0472-z doi (NATIONALLICENCE)springer-10.1007/s11095-011-0472-z Crystallization of Organic Glasses: Effects of Polymer Additives on Bulk and Surface Crystal Growth in Amorphous Nifedipine [Elektronische Daten] [Ting Cai, Lei Zhu, Lian Yu] ABSTRACT: Purpose: To study the influence of polymer additives on bulk and surface crystal growth in organic glasses (amorphous solids), which are being investigated for delivering poorly soluble drugs and in this role must resist crystallization. Recent studies have discovered new modes of crystal growth that emerge as organic liquids are cooled to form glasses: one existing in the bulk (GC growth) and another at the surface, both leading to crystal growth much faster than predicted by standard theories. Methods: Bulk and surface crystal growth rates were measured in nifedipine glasses doped with polyvinylpyrrolidone (PVP) of different molecular weights. AFM enabled observation of the microstructure of surface-growing crystals. Results: Polymer additives influence bulk and surface crystal growth differently. For every weight percent of PVP added, surface crystal growth of nifedipine slows by two times at 12°C below T g, whereas bulk crystal growth slows by 10 times. In contrast to the polymers, the VP dimer had little effect on crystal growth. Conclusions: Polymer additives inhibit crystal growth in nifedipine glasses more strongly in the bulk than at the surface. The effectiveness of crystallization inhibitors depends not only on intermolecular interactions but also on molecular sizes. Springer Science+Business Media, LLC, 2011 amorphous solid nationallicence bulk nationallicence crystal growth nationallicence glass nationallicence polymer dispersion nationallicence surface nationallicence Cai Ting School of Pharmacy and Department of Chemistry, University of Wisconsin - Madison, 53705, Madison, Wisconsin, USA aut Zhu Lei School of Pharmacy and Department of Chemistry, University of Wisconsin - Madison, 53705, Madison, Wisconsin, USA aut Yu Lian School of Pharmacy and Department of Chemistry, University of Wisconsin - Madison, 53705, Madison, Wisconsin, USA aut Pharmaceutical Research Springer US; http://www.springer-ny.com 28/10(2011-10-01), 2458-2466 0724-8741 28:10<2458 2011 28 11095 https://doi.org/10.1007/s11095-011-0472-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11095-011-0472-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cai Ting School of Pharmacy and Department of Chemistry, University of Wisconsin - Madison, 53705, Madison, Wisconsin, USA aut NATIONALLICENCE 700 1- Zhu Lei School of Pharmacy and Department of Chemistry, University of Wisconsin - Madison, 53705, Madison, Wisconsin, USA aut NATIONALLICENCE 700 1- Yu Lian School of Pharmacy and Department of Chemistry, University of Wisconsin - Madison, 53705, Madison, Wisconsin, USA aut NATIONALLICENCE 773 0- Pharmaceutical Research Springer US; http://www.springer-ny.com 28/10(2011-10-01), 2458-2466 0724-8741 28:10<2458 2011 28 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer