Comparative evaluation study of polycomplex carriers based on Eudragit® EPO/S100 copolymers prepared in different media

• Published in: Polymers for advanced technologies 2021-07, Vol.32 (7), p.2761-2769
• Main Authors: Bukhovets, Aleksandra V., Sitenkov, Alexander Y., Moustafine, Rouslan I.
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Buffers; Chemical analysis; controlled drug delivery; Copolymers; drug delivery systems; Ethanol; Eudragit; Gastrointestinal system; interpolyelectrolyte complexes; interpolymer complexes; Sustained release; Swelling; Theophylline; Thermal analysis
• ISSN: 1042-7147; 1099-1581
• DOI: 10.1002/pat.5284

Interpolymer complexes (IPC) Eudragit® EPO/S100 were prepared in different media (water pH of 7.0 and ethanol). According to the elemental analysis, FTIR spectroscopy, and thermal analysis data, IPC prepared in aqueous media (denoted as interpolyelectrolyte complexes—IPECs) is stabilized predominantly by ionic intermacromolecular bonds and has a composition close to equimolar. However, polycomplexes formed in nonaqueous (ethanol) media (denoted as IPC) are stabilized by both hydrogen and ionic bonds and characterized by an almost twofold excess of Eudragit® S100. All samples do not include free copolymer domains. IPECs and IPCs have different behavior in the buffer media mimicking the gastrointestinal tract. Matrices of IPECs are characterized by the surface erosion and pH‐independent swelling profiles with low values of a swelling degree. Matrices of the IPCs swell significantly in the buffer media with pH 1.2, 5.8, and 6.8 with subsequent decrease in the swelling degree due to the surface erosion. According to the assessment of release of the model active pharmaceutical ingredient (API), IPECs are prospective carriers for sustained delivery of II class Biopharmaceutical Classification System (BCS) drug (diclofenac sodium). At the same time, IPCs provide sustained release of the II class BCS and prolonged release of the I class BCS drug (theophylline).