Portal de Periódicos da CAPES

Verapamil Hydrochloride Release Characteristics from New Copolymer Zwitterionic Matrix Tablets

2008; Taylor & Francis; Volume: 13; Issue: 4 Linguagem: Inglês

10.1080/10837450802089180

1097-9867

Bistra Kostova, Elena Kamenska, Ivo Ivanov, Georgi Momekov, Dimitar Rachev, George Georgiev,

Surfactants and Colloidal Systems

The aim of this study was to synthesize stable copolymer (vinyl acetate-co-3-dimethyl[methacryloyloxyethyl] ammonium propane sulfоnate) zwitterionic latex with different compositions for the first time by emulsifier-free emulsion copolymerization. Throughout the course of the study, a proposal was made for the explanation of the relationship between the “overshooting” phenomenon (a swelling kinetics with a maximum) and the specific self-association of the zwitterionic copolymers. The zwitterionic monomer unit mole fraction, pH, and ionic strength effects on this relationship, on the swelling kinetics of the zwitterionic copolymers, and on the sustained verapamil hydrochloride release from the model tablets were established by the study's authors.