Spherical agglomeration of telmisartan by quasi emulsion solvent diffusion technique to improve the solubility and dissolution rate

Abstract

Spherical agglomerates of telmisartan (TEL) were prepared with and without the polymers viz. Polxamer F68, Gelucire 50/13, hydroxylpropyl methylcellulose (HPMC E15) and polyvinylpyrrolidone (PVP K90) at different concentrations by quasi emulsion solvent diffusion (QESD) technique, using the solvent system consisting of N,N dimethyl formamide, water and chloroform as good, poor solvent and bridging liquid respectively. All the prepared agglomerates were characterized for yield, particle size, flow properties, drug content, solubility, in vitro dissolution release, fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Results of physical evaluation indicates that, all the prepared agglomerates showed improvement in flowability, compactability, solubility and dissolution rate of TEL compared with pure TEL. Agglomerates prepared using polymers showed further improvement in solubility and dissolution rate compared to agglomerates with no drug, which in turn depends on type and concentration of polymer used. Spherical agglomerates containing 0.05 % Poloxamer F68 was considered optimum as it showed 9.96 and 4.48 folds improvement in solubility and dissolution rate respectively, compared with pure drug. FTIR spectrums of agglomerates indicated no incompatibility between the drug and solvents/ polymers used. PXRD patterns showed the agglomerates retained their crystal characteristics with reduced crystallanity or partial amorphization of TEL. SEM images confirm the spherical shape of agglomerates and their micro porous, rough and crevice surface. Thus, spherically agglomeration of TEL with polymers is a successful approach for improving the micromeritic, solid state and physicochemical properties.