RESUMO
The surface properties of hybrid materials (potential carriers for sustained release of active agents) have been examined by inverse gas chromatography. A nonsteroidal anti-inflammatory agent, ibuprofen, was used as a model for active compound. The following parameters have been used to characterize the interactions between the constituents of the hybrid material and the active agent: dispersive component of the surface free energy γ(D) S ; KA and KD parameters describing the acidity and basicity, respectively; and Flory-Huggins parameter χ'23 (the magnitude of interactions). Principal component analysis (PCA) and the procedure based on the sum of ranking differences (SRD) were applied for the selection of hybrid materials and parameters for characterization of these materials. One loose cluster found by PCA grouping of hybrid materials is refined by SRD analysis: SRD grouping indicates three groups having somewhat dissimilar properties.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Cromatografia Gasosa/métodos , Portadores de Fármacos/química , Ibuprofeno/administração & dosagem , Análise de Componente Principal , Propriedades de SuperfícieRESUMO
The ability of organic-inorganic hybrid materials to act as drug release-modifying agents was examined. In this study, ibuprofen, a non-steroidal anti-inflammatory drug was used as a model active pharmaceutical ingredient. The physicochemical properties of individual components of the hybrids, as well as these for two- and three-component systems were examined by inverse gas chromatography. The dispersive component of the free surface energy (γ(S)(D)), K(A) and K(D) parameters describing acidity and basicity of hybrid materials, respectively, as well as Flory-Huggins parameters were determined. χ(12)(∞) and [Formula: see text] parameters characterize the interactions between the hybrids and a test solute, or interactions between the drug and inorganic-organic materials, respectively. Additionally, Brunauer-Emmett-Teller (BET) method was used to characterize adsorption activity of the studied materials. The prepared hybrid materials were also characterized by Fourier transform infra-red (FTIR) spectroscopy. The release profiles of ibuprofen for the created hybrid materials were determined. Relationship between the physicochemical activity of hybrid materials and ibuprofen release was presented and discussed.
Assuntos
Anti-Inflamatórios não Esteroides/química , Cromatografia Gasosa/métodos , Ibuprofeno/química , Dióxido de Silício/química , Adsorção , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de SuperfícieRESUMO
Inverse gas chromatography (IGC) at infinite dilution was applied to evaluate the surface properties of sorbents and the effect of different carrier gas humidity. They were stored in different environmental humidity - 29%, 40%, and 80%. The dispersive components of the surface free energy of the zeolites and perlite were determined by Schulz-Lavielle method, whereas their tendency to undergo specific interactions was estimated basing on the electron donor-acceptor approach presented by Flour and Papirer. Surface parameters were used to monitor the changes of the properties caused by the humidity of the storage environment as well as of RH of carrier gas. The increase of humidity of storage environment caused a decrease of sorbents surface activity and increase the ability to specific interaction.
