CIDEPINT   05376
CENTRO DE INVESTIGACIONES EN TECNOLOGIA DE PINTURAS
Unidad Ejecutora - UE
artículos
Título:
Dexamethasone 21 phosphate loading and release from pH sensitive copolymers of 2-hydroxyethyl methacrylate and 2-(diisopropylamino)ethyl methacrylate
Autor/es:
P.A. FACCIA; F. PARDINI; J.I. AMALVY
Revista:
Int. J. Pharm. Sci. Res. Conference Proceeding
Editorial:
International Journal of Pharmaceutical Sciences and Research
Referencias:
Año: 2015 p. 91 - 91
Resumen:
Smart polymers like pH-sensitive systems can improve the pharmacological treatment of diseases.Topical application is perhaps the most typical treatment practice in ophthalmic therapies; however it isinefficient and sometimes produces side effects. A possibility to improve drug residence time andbioavailability is the use of a pH-sensitive hydrogel as a vehicle to control the drug delivery.In this workthe behavior of copolymers containing 2-hydroxyethyl methacrylate (HEMA) with different proportionsof 2-(diisopropylamino) ethyl methacrylate (DPA) and different amounts of cross-linker agent, ethyleneglycol dimethacrylate (EGDMA) are evaluated as drug delivery systems for ophthalmic therapies. Drugload and release studies at different pH values were evaluated using dexamethasone-21 phosphate (DXP)as a model drug. The interaction between the polymer matrix and the drug was studied by IRspectroscopy (FTIR), and drug distribution and film morphology at different pH valueswere studiedbyscanning electron microscopy (SEM). The results show thatthe loading of DXP increaseswith DPAcontent and crosslinking degree. Also the incorporation of DXP into the matrix depends on the mediumpH and increase at basic pH. SEM images show important morphological changes when varying themedium pH and it can be seen the presence of the DXP loading in the polymer matrix. FTIR spectra ofcopolymers show an interaction between the drug and the polymer matrix through the shifting of thecarbonyl stretching band. The release of DXP from copolymers of HEMA and DPA is sensitive to smallpH variations in the range of 7.00 and 7.80. Kinetics releases shows case-II or anomalous diffusionbehavior depending on the HEMA/DPA ratio.At medium ocular pH (7.40) the exponents values (n)obtained for the hydrogels containing 10 wt. % of DPA are close to 1.0, suggesting a case-II transport andfor hydrogels containing 30 wt. % of DPAthe n values are between 0.5 and 1 indicating an anomalousbehavior.