Investigation of Potential Ionic Interactions Between Anionic and Cationic Polymethacrylates of Multiple Coatings of Novel Colonic Delivery System

Abstract

The objective of this work was to investigate potential interactions between anionic (Eudragit FS) and cationic (Eudragit RL) polymethacrylates of multiple coatings of a novel colonic drug delivery system. Aqueous films of pure polymers Eudragit FS (FS) and Eudragit RL (RL) and their superimposedfilm (FS-RL) were cast on glass slabs. The potential ionic interactions were studied by analysing the dried films using differential scanning calorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR). The glass transition temperatures (Tg) of pure RL and FS were 60 degrees C and 22 degrees C, respectively; FS-RL showed two distinct glass transitions at 59 degrees C and 24 degrees C in the second heating cycle. In the 13C-MAS spectra of the samples in the solid state, no shifts of the resonance could be detected in the superimposed film compared with the pure polymers. The FT-IR spectra of the superimposed film did not show any significant shift of the bands of the -NMe3+ group of RL and the -COO- function of FS compared with the spectra of the pure polymers. No ionic interactions between anionic and cationic polymethacrylates were revealed by DSC, FT-IR, and NMR.

Interpolymer combinations of chemically complementary grades of Eudragit copolymers: a new direction in the design of peroral solid dosage forms of drug delivery systems with controlled release (review)

“…They modeled the conditions for preparing the DF by preparing bilayer systems and layering a preliminarily dried coating onto another in the same sequence that was used to prepare the pellets. However, interpolymer interactions were not observed by physicochemical analysis of the prepared bilayer films using IR and NMR spectroscopy and DSC [39].…”

Structural Transformations During Swelling of Polycomplex Matrices Based on Countercharged (meth)acrylate Copolymers (EudragitR EPO/EudragitR L 100-55)

“…Trials were performed to evaluate potential ionic interactions between RL30D (RS30D) and FS30D in a doublelayer-coated pellet. 4,19 Using different analytical techniques (FTIR, DSC, and NMR), it was possible to show that no significant interaction between these oppositely charged copolymers was present. 19 Moreover, recently, novel sustained release of a tablet formulation using a binary mixture of E100 and L100 (S100) in their salt form was performed.…”

“…4,19 Using different analytical techniques (FTIR, DSC, and NMR), it was possible to show that no significant interaction between these oppositely charged copolymers was present. 19 Moreover, recently, novel sustained release of a tablet formulation using a binary mixture of E100 and L100 (S100) in their salt form was performed. 20,21 Results from swelling studies strongly supported the presence of ionic interaction between E100-citrate and L100-Na within polymer matrices that provide a pH-independent and sustained release behavior of a model drug from the tablets.…”

Comparative study of structural and compositional changes of polycomplex matrices based on Eudragit® EPO and Eudragit® L100

“…Apparently assumptions about visible changes in release profiles that were caused by the compositional combination of oppositely charged brands of Eudragit ® copolymers turned out in most instances to be incorrect. An actual attempt to prove that Eudragit copolymers interact was made in only one study [5]. Thus, systematic investigations on the synthesis and chemical and pharmaceutical evaluation of interpolyelectrolyte complexes (IPECs) based on oppositely charged Eudragit ® copolymers compared with the pure copolymers, their physical mixtures, and other types of Eudragit ® with recommendations for their use as drug carriers were first made by our group [6 -11].…”