Microscopic Fourier transform infrared/differential scanning calorimetry system used to study the different thermal behaviors of polymethacrylate copolymers of eudragits RS, RL, E 30D, or E

The thermal stability of Eudragits RL, RS, E 30D, and E films was qualitatively investigated by the reflectance Fourier transform infrared microspectroscopy equipped with differential scanning calorimetry (FTIR/DSC microscopic system). DSC and thermogravimetric analysis (TGA) were also used to study the thermal behavior of the granules of the raw material and the film of these polymers. The results indicate that the Eudragit RL, RS, or E 30D polymer exhibited a higher thermal-stable behavior, but Eudragit E easily formed the six-membered cyclic anhydride through heating process via the inter- or intramolecular ester condensation. The leaving group in Eudragit E molecule was larger than that in Eudragit E 30D, and the leaving group of salt in Eudragit RS or RL was too stable to polycondense. The DSC thermograms and TGA curve also confirmed this result. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 829–835, 2000

[1]  S. Lin.  Isolation and solid-state characteristics of a new crystal form of indomethacin. , 1992, Journal of pharmaceutical sciences.

[2]  Chau‐Jen Lee,et al.  Application of a new micro FT-IR/DSC technique to the study of the curing kinetics of silicone elastomer , 1994 .

[3]  S. Lin,et al.  Microscopic FT‐IR/DSC combined system used to investigate the thermotropic behavior of lipid in porcine stratum corneum after pretreatment with skin penetration enhancers , 1996, Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging.

[4]  K. Duan,et al.  Simultaneous determination of the protein conversion process in porcine stratum corneum after pretreatment with skin enhancers by a combined microscopic FT-IR/DSC system , 1996 .

[5]  Shan-Yang Lin,et al.  Formation of six-membered cyclic anhydrides by thermally induced intramolecular ester condensation in Eudragit E film , 1999 .

[6]  S. Lin,et al.  Thermal stability and reversibility of secondary conformation of alpha-crystallin membrane during repeated heating processes. , 1998, Biophysical chemistry.

[7]  G. Hsiue,et al.  Temperature-dependent anhydride formation of Eudragit L-100 films determined by reflectance FTi.r./d.s.c. microspectroscopy , 1995 .

[8]  Shan‐Yang Lin,et al.  Lipid and Protein Thermotropic Transition of Porcine Stratum Corneum by Microscopic Calorimetry and Infrared Spectroscopy , 1994 .

[9]  G. Hsiue,et al.  Isothermal kinetics of anhydride formation in Eudragit L-100 films determined by reflectance FT i.r./d.s.c. microspectroscopy , 1996 .

[10]  D. L. Pavia,et al.  Introduction to spectroscopy : a guide for students of organic chemistry , 1996 .

[11]  Ko-Shao Chen,et al.  Thermophysical Properties of Cholesteryl Oleyl Carbonate Determined with Microscopic Ftir/Dsc System , 1995 .

[12]  G. Hsiue,et al.  A reflectance FTIR/DSC microspectroscopic study of the nonisothermal kinetics of anhydride formation in Eudragit L-100 films , 1995 .

[13]  Raymond C Rowe,et al.  Handbook of Pharmaceutical Excipients , 1994 .