Original scientific paper

https://doi.org/10.2478/v10007-007-0034-4

New co-polymer zwitterionic matrices for sustained release of verapamil hydrochloride

BISTRA KOSTOVA
DIMITAR RACHEV

Abstract

Stable co-polymer [vinyl acetate-co-3-dimethyl(methacryloyloxyethyl)ammonium propane sulfоnate, p(VA-co-DMAPS)] latex of different compositions has been synthesized for the first time by emulsifier-free emulsion copolymerization. The unusual “overshooting” behavior of the co-polymer tablets has been explained by the formation of specific clusters from the opposite oriented dipoles  zwitterionic species. The change of their concentration with the DMAPS unit fraction (mDMAPS), pH and ionic strength has been considered responsible for the differences observed in the swelling kinetics. The results obtained prove that mDMAPS and ionic strength could be used to control the swelling degree of the p(VA-co-DMAPS) matrices. In this way, p(VA-co-DMAPS) matrices could be effectively used to control the sustained release of drugs with basic properties like verapamil hydrochloride from model tablets.

Keywords

co-polymer [vinyl acetate-co-3-dimethyl(methacryloyloxyethyl)ammonium propane sulfоnate; emulsifier-free emulsion copolymerization; polyzwitterion; dipole-dipole clusters; swelling degree; matrix tablets; drug delivery

Hrčak ID:

17303

URI

https://hrcak.srce.hr/17303

Publication date:

1.12.2007.

Article data in other languages: croatian

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