Development, characterization and solubility enhancement of poorly water soluble drug telmisartan by polymer enriched bridging liquid technique using peg 4000 as hydrophilic polymer

Abstract

The solubility and bioavailability enhancement of poorly water soluble drugs has been a foremost challenge in formulation development. Telmisartan belonging to Angiotension II receptor antagonist, extensively used candidate for the treatment of hypertension possess poor water solubility and bioavailability. Polymer Enriched Bridging Liquid (PEBL) method was adopted here for enhancing the flow properties and solubility of Telmisartan. The techniques involve the incorporation of a hydrophilic polymer, PEG4000 into the bridging liquid during the crystallisation process. The drug content determination suggested the better incorporation of polymer into the crystal aggregates. The FTIR analysis showed the absence of any chemical interaction. The DSC analysis showed a significant reduction in the enthalpy and melting point. The crystallinity of Telmisartan was reduced from 50.789 to 34.655% indicated by the reduction in peak intensity analysis and peak area calculation by X-Ray diffraction. The SEM analysis revealed the spherical nature of crystals resulting in the improvement of flow properties. The saturation solubility analysis revealed that the formulation STPG03 has shown 25.86 fold increase in the solubility in water and 24.217 folds in pH7.5 Phosphate buffer. The in vitro dissolution data also supported the results of solubility analysis. Hence PEBL technique provided a better alternative to enhance the flow characteristics, solubility, dissolution and bioavailability of Telmisartan.