Study of factors affecting the in vitro release of diclofenac sodium from hypromelose-based gels

The aim of our study was to identify factors affecting the in vitro release diclofenac sodium (DS) from hypromellose-based gels (HPMC).
 Materials and methods. Gels with HPMC liquids without were studied by viscosity-rotating viscometer method spin probe electron paramagnetic resonance spectroscopy. Rheograms used determine flow behavior apparent viscosity, EPR spectra rotational correlation time (τ–1) dissolved probes. tests performed using vertical diffusion cells according a validated procedure. assay DS isopropyl alcohol (IPA) receptor medium high performance liquid chromatography (HPLC) gas (GC) procedures, water content determined semi-micro method.
 Results. viscosity increased increasing depended on grade. did not affect values τ–1 In viscous Newtonian fluids, composition which corresponded dispersion gels, identical range rapid rotation, is prerequisite for similar substances liquids. It shown that HPMC-based gel terms parameters IPA equivalent. During testing its concentration dispersed state DS. When changed 45.0 % 22.5 %, absorption decreased, increased, due decrease solubility gel.
 Conclusions. HPMC, provided value probes gels. equivalent IPA. altered proportionally state. As but because