Intermacromolecular interactions with Eudragit® copolymers as a new principle of the microparticulate oral drug delivery systems development

The main trends of combining the chemically complementary types of (meth)acrylic copolymers of pharmaceutical-grade - Eudragit® in oral microparticulate systems with modified release (spheres, granules, capsules, etc.) - and the technological methods used in their manufacture, including various types of coating (single-layer, multi-layered, combined) are considered. It is noted that the processes that control the drugs release are based on pH-dependent intermacromolecular interaction of reactive groups between a pair of opposite charged Eudragit® copolymers both inside of spherical micro-matrix and inside the multilayer and combined coatings, allowing regulating both the degree and time of active pharmaceutical ingredients (API) release from pharmaceutical form. Using this principle allows to develop time-sensitive and pH-sensitive systems with a targeted API delivery to predetermined parts of the gastrointestinal tract, preferably to the colon, which is not only the optimal zone for absorption of many API, but also often requires treatment of inflammatory diseases of different origin. Analysis of these processes is of key importance to a better understanding of the mechanisms underlying the API transport from considered systems types, methods of their correction, modification of macromolecular parameters (such as the copolymer units charge density, the stoichiometry of the produced composition, the hydrophilic and hydrophobic fragments ratio in the polycomplexes structure affecting the swelling and resulting permeability of the system), as well as perspectives of (meth)acrylate polycomplexes use as a new class of carriers in the design of modern self-regulating, depending on the gastrointestinal tract physiological fluids pH, microparticulate oral API delivery systems.