RESUMO
The design of new interpolyelectrolyte complexes (IPEC) between countercharged polymers (Eudragit EPO (EPO) and Eudragit L100 (L100)) was investigated. The formation and chemical composition of three new IPECs between EPO and L100 was established by elemental analysis. The structure and solid state properties of the synthesized IPEC were investigated using Fourier transform infrared (FTIR) spectroscopy and modulated temperatre differential scanning calorimetry (MTDSC). The binding ratio of a unit molecule of EPO with L100 was found to range between 1:0.98 (Z = 1.02) and 1:0.50 (Z = 2.00) while increasing the pH from 6.0 to 7.0. As a result of electrostatic interaction between the copolymer chains, the glass transition temperature of the IPEC increased significantly. Considerable pH-sensitive swelling in acidic and neutral media was observed for different type of IPECs. Through evaluation of diffusion-transportation properties of the IPECs, basic mechanisms controlling the delivery of chemically different drugs (diclofenac sodium and theophylline) were obtained. The results of swelling and release of the model drugs from the polycomplex matrices confirm that they have potential to be used in oral controlled drug delivery.
Assuntos
Sistemas de Liberação de Medicamentos/métodos , Ácidos Polimetacrílicos/química , Varredura Diferencial de Calorimetria , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de FourierAssuntos
Acrilatos/química , Resinas Acrílicas/química , Polímeros/química , Acrilatos/farmacocinética , Resinas Acrílicas/farmacocinética , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos/métodos , Eletrólitos/química , Eletrólitos/farmacocinética , Trato Gastrointestinal/metabolismo , Cinética , Modelos Biológicos , Polímeros/farmacocinéticaAssuntos
Resinas Acrílicas/química , Portadores de Fármacos/química , Ácidos Polimetacrílicos/química , Resinas Acrílicas/farmacocinética , Portadores de Fármacos/farmacocinética , Eletrólitos/química , Eletrólitos/farmacocinética , Trato Gastrointestinal/metabolismo , Modelos Biológicos , Ácidos Polimetacrílicos/farmacocinéticaAssuntos
Resinas Acrílicas/química , Quitosana/química , Colo/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Resinas Acrílicas/administração & dosagem , Resinas Acrílicas/farmacocinética , Administração Oral , Quitosana/administração & dosagem , Quitosana/farmacocinética , Eletrólitos/administração & dosagem , Eletrólitos/química , Eletrólitos/farmacocinéticaRESUMO
With a view to the application in oral drug delivery formulations, the possibility to form interpolyelectrolyte complexes (IPEC) of Eudragit E 100 (EE) with sodium alginate (AL) was investigated, employing turbidimetry, apparent viscosity measurements, FT-IR and elementary analysis. The interaction or binding ratio of a unit molecule of AL with EE was largely affected by the pH value of the media, showing a change from 1.5:1 to 1:1.25 (0.66Assuntos
Acrilatos/química
, Alginatos/química
, Eletrólitos/química
, Ácido Glucurônico/química
, Ácidos Hexurônicos/química
, Polímeros/química
, Acrilatos/análise
, Alginatos/análise
, Eletrólitos/análise
, Ácido Glucurônico/análise
, Ácidos Hexurônicos/análise
, Polímeros/análise
RESUMO
With a view to the application in oral controlled drug delivery systems, the formation of interpolyelectrolyte complexes (IPEC) between Eudragit E100 (EE) and Eudragit L100 (EL) was investigated, using turbidimetry, solution viscosity measurements and elementary analysis. The structure of the synthesized IPEC was investigated by using FT-IR spectroscopy. The binding ratio of a unit molecule of EL with EE was found to be approximately 1:1 in pH 6.0. Based on the results of elementary analysis, and FT-IR, the binding ratio of each component in the solid complexes was very close to that observed in turbidity and viscosity measurements and indicate that the synthesized products can be considered as IPEC. Due to the structure of the IPEC, two maxima were observed in the swelling behaviour as a function of pH. The release of the model drug ibuprofen was significantly retarded from tablets made up of the IPEC.