Development, Optimization and Characterization of Eudraguard®-Based Microparticles for Colon Delivery

Abstract

Development of pH-dependent systems for colon delivery of natural active ingredients is an attractive area of research in the field of nutraceutical products. This study was focused on Eudraguard® resins, that are methacrylate copolymers approved as “food grade” by European Commission and useful for the production of food supplements. In particular, Eudraguard® Biotic (EUG-B), characterized by a pH-dependent solubility and Eudraguard® Control (EUG-C), whose chemical properties support a prolonged release of the encapsulated compounds, were tested. To obtain EUG microparticles, different preparation techniques were tested, in order to optimize the preparation method and observe the effect upon drug encapsulation and specific colonic release. Unloaded microparticles were initially produced to evaluate the influence of polymer characteristics on the formulation process; subsequently microparticles loaded with quercetin (QUE) as a low solubility model drug were prepared. The characterization of microparticles in the solid-state (FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry) indicated that QUE was uniformly dispersed in a non-crystalline state in the polymeric network, without strong signs of chemical interactions. Finally, to assess the ability of EUG-C and EUG-B to control the drug release in the gastric environment, and to allow an increased release at a colonic level, suitable in vitro release tests were carried out by simulating the pH variations along the gastro-intestinal tract. Among the evaluated preparation methods, those in which an aqueous phase was not present, and in particular the emulsion-solvent evaporation method produced the best microparticle systems. The in vitro tests showed a limited drug release at a gastric level and a good specific colon release.

Gastro-Resistant Microparticles Produced by Spray-Drying as Controlled Release Systems for Liposoluble Vitamins

“…Retinyl acetate (microparticle formulations C1 and C2), cholecalciferol (microparticle formulations D1 and D2) and α-tocopherol (microparticle formulations E1 and E2) instead had fusion peaks around 45 °C, 60 °C and 90 °C, respectively [ 32 , 34 ]. The Eudraguard Biotic and CAP thermograms showed an endothermic peak, respectively, at around 50 °C and 170 °C, attributable to the glass transition of the amorphous polymer (T g ) [ 35 , 36 ]. All of the microparticle formulations containing WPs (A3, B3, C3, D3, E3) showed a single broad peak around 130 °C, slightly different from the characteristic peak of decomposition of whey proteins around 120 °C [ 17 ].…”

Food-grade polymers: A new vision in the controlled release of bioactive substances

“…In Figure 1 the food-grade polymers discussed from this paper are summarized, whose physico-chemical properties are gathered in Table 1. --Synthetic methacrylat e copolymers [55,80] WVP, Water vapor permeability (expressed as g . mm/m2 .…”

“…This is a significant advancement in the field of pharmaceuticals. [52][53][54][55][56][57]. Eudraguard ® Biotic and Control materials are interesting for developing delivery systems targeted to colon.…”

Eudraguard® Natural and Protect: New “Food Grade” Matrices for the Delivery of an Extract from Sorbus domestica L. Leaves Active on the α-Glucosidase Enzyme

“…There are only a few papers on these coating polymers in the literature. Moreover, such research focuses on the use of the polymers to coat granules and tablets [ 1 ] or to encapsulate matrices using different solvent evaporation/emulsion techniques [ 3 , 4 , 5 ]. None of the papers investigate the microencapsulation ability with spray-drying.…”