PHYSICOCHEMICAL INTERACTION OF NAPROXEN WITH ALUMINIUM HYDROXIDE AND ITS EFFECT ON DISSOLUTION

The interaction study of naproxen with aluminium hydroxide has been carried out in both solid state and wet state. Naproxen was co-milled in the solid state and co-lyophilized after overnight wet equilibration in different weight ratios. Physicochemical characterization of the interaction was carried out using analytical techniques such as Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM) studies. In vitro dissolution studies were also performed to examine the effect of interaction on dissolution. FTIR spectra suggested an acid base interaction between the carboxylic acid containing naproxen and aluminium hydroxide. DSC thermogram confirmed the absence of complexation between naproxen-aluminium hydroxide and SEM study indicated the presence of stabilized microparticles containing cluster of nano- and submicron drug crystals associated with aluminium hydroxide. In vitro dissolution studies revealed the improved release of naproxen from formulated powder samples