Interpolymer Complexes of Eudragit® Copolymers as Novel Carriers for Colon-Specific Drug Delivery.

Rouslan I Moustafine,Aleksandra V Bukhovets,Vitaliy V Khutoryanskiy,Nikoletta Fotaki

doi:10.3390/polym12071459

Rouslan I Moustafine, Aleksandra V Bukhovets + Show 2 more

Open Access

https://doi.org/10.3390/polym12071459

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Abstract

Interpolymer complexes (IPC) based on Eudragit® EPO and Eudragit® S100 were investigated as potential carriers for oral controlled drug delivery to the colon. IPC samples were prepared by mixing copolymer solutions in organic solvents (ethanol, isopropanol:acetone mixture (60:40, % v/v) and tetrahydrofuran). According to the data of elemental analysis, FTIR-spectroscopy, X-ray photoelectron spectroscopy and thermal analysis these IPCs have excess of anionic copolymer (Eudragit® S100) in their structure; they are stabilized by hydrogen and ionic intermacromolecular bonds and do not include free copolymer domains. IPC have pH-independent swelling properties in the media mimicking gastrointestinal tract (GIT) conditions and provide colon-specific delivery of indomethacin in buffer solutions (pH 1.2; 5.8; 6.8; 7.4) and in biorelevant media (fasted state simulated gastric fluid, fasted state simulated intestinal fluid—version 2 and fasted stated simulated colonic fluid).

Highlights

Polymethacrylates of Eudragit® series from Evonik Röhm GmbH are widely used for preparation of oral drug delivery systems [1,2,3,4]
Interactions between oppositely charged polymers are traditionally studied in aqueous media, which favors electrostatic attraction forces and additional stabilization of interpolyelectrolyte complexes by hydrophobic effects resulting from the presence of nonpolar groups in both polymers [6,55]
When the solvent medium is switched from aqueous to a fully or partially organic this may substantially affect the intensity of interactions, the structure of polycomplexes formed and in some cases, it may even prevent the formation of interpolymer complexes (IPC) [56,57]

Summary

Introduction

Polymethacrylates of Eudragit® series from Evonik Röhm GmbH are widely used for preparation of oral drug delivery systems [1,2,3,4]. Due to their structure Eudragit® -copolymers can participate in intermolecular interactions with other polymers and form interpolymer complexes (IPC). There are several studies reporting the use of IPC based on Eudragit® copolymers as drug carriers. There are IPC based on two oppositely charged Eudragit® copolymers that can be used as drug delivery systems [1,18,19,20,21,22,23]

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