Physical chemistry behavior of enteric polymer in drug release systems.

摘要: We report an analysis based on the electrical impedance (EI) spectrum of samples enteric random copolymer poly-methacrylic acid-co-methyl methacrylate as a function pH media. Important aspects charge transport and conformational processes in polymer can be identified by mapping complex frequency, which allows that some parallelism between titration EI measurements obtained. However, latter technique reveals details this equilibrium not appear using common methods. The relaxation frequency observed act probe for detection phase transitions changes polymeric chains, once distribution size particles related with parameter. progressive introduction alkali variation 4 10 are associated three steps process, to shift from precipitated solid or suspension, colloidal-like dispersion complete solubilization copolymer. All those experimental features were reflected simultaneously turning point plots impedance, visible absorption addition giving better detailed insight these processes.