Synthesis and Characterization of Zwitterionic Co-polymers as Matrices for Sustained Metoprolol Tartrate Delivery

Abstract

Very stable co-polymer (vinyl acetate (VA)-co-3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) (p(VA-co-DMAPS)) latexes with different compositions have been synthesized by emulsifier-free emulsion co-polymerization. The dry p(VA-co-DMAPS)s have been used in the preparation of drug tablets for sustained Metoprolol tartrate release. It has been shown that the tablet swelling depends on the mol fraction of DMAPS monomer units (m(DMAPS)), pH and ionic strength (I). An original explanation, based on the swelling behavior of p(VA-co-DMAPS), has been proposed for the "overshooting" phenomenon observed. It assumes the formation of hydrophilic domains with a higher m(DMAPS) in the co-polymer tablets. The formation of dipole-dipole clusters between the DMAPS units at different m(DMAPS) and I are the main cause for the established differences in both the swelling kinetics of the p(VA-co-DMAPS) matrices and Metoprolol tartrate release. The obtained results show that for p(VA-co-DMAPS) matrices-based tablets controlled sustained Metoprolol tartrate release can be realized just by varying two parameters, co-polymer composition and I.

Design and Concept of Polyzwitterionic Copolymer Microgel Drug Delivery Systems In Situ Loaded with Non-steroidal Anti-inflammatory Ibuprofen

“…Even before the initiation of EEC two phases are formed: upper oil, containing dissolved Ibu in VA and lower aqueous phase consisting of dissolved DMAPS and PPS in water. In our previous work, it was established that formed molecules of p(VA-co-DMAPS) act as an emulsifier during EEC of VA and DMAPS (10). At the initiation of EEC, copolymer micelles are formed in the aqueous medium with a hydrophobic core, containing molecules of VA and Ibu, and a hydrophilic shell of zwitterionic outside groups of DMAPS.…”

“…In our previous paper (9,10), were presented the synthesis and characterization of copolymer nano-sized latex particles based on vinyl acetate (VA) and 3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) (p(VA-co-DMAPS)) prepared by emulsifier-free emulsion copolymerization (EEC) in water. It was established that the change of the initial monomer feed led to changes in the type and mechanism of EEC, as well as the shape, the average diameter and the morphology of the copolymer nanoparticles.…”

One-pot synthesis of micron-sized polybetaine particles; innovative use of supercritical carbon dioxide

“…However, no detailed analysis on the particle morphology or size dispersity was reported. 17 Membranes containing betaine copolymer colloid particles (synthesised from hydroxyethyl acrylate (HEA) and DMAPS) have been reported to display tuneable selectivity, improved antifouling properties and reduced phase separation (and therefore higher membrane stability) when compared to membranes containing inorganic nanoparticles, highlighting the benefits of using such polybetaine colloids. 18 Again, little characterisation data for the particles was given in this case.…”

Study of the Potential of Amphiphilic Conetworks Based on Poly(2-ethyl-2-oxazoline) as New Platforms for Delivery of Drugs with Limited Solubility

“…In this regard, stimuli-responsive polymers and hydrogels are of particular importance (1). The ability of these systems to respond to stimuli such as temperature, pH, ionic strength, and electric field could enhance the efficiency of drug loading and release, and optimize the delivery of therapeutic molecules to a specific target area (2)(3)(4)(5)(6). Temperature is among the most commonly used external stimuli in the responsive polymer systems.…”