FORMULATION AND CHARACTERIZATION OF LIQUISOLID TABLETS OF VALSARTAN FOR IMPROVEMENT OF DISSOLUTION RATE

Objective: The solubility and dissolution properties of any drug are vital determinants of its oral bioavailability. The objective of this studyis to screening of non-volatile solvent in which drug shows maximum solubility and then formulation of different liquisolid (LS) compacts usingmathematical equations to increase the dissolution rate of drug.Materials and Methods: Different LS compacts were prepared using a mathematical model for calculating required quantities of powder andliquid ingredients to produce an acceptably flowable and compressible admixture. Avicel PH 102, aerosil 200 and crospovidone were employedas a carrier, coating material and disintegrant, respectively. The prepared LS systems were evaluated for their flow behavior and possible drugexcipientinteractions by infrared (IR) spectra analysis and X-ray diffraction (XRD). Morphological changes in the final formulation were investigatedby scanning electron microscopy (SEM), liquisolid compacts were prepared and evaluated for their tableting properties.Results: Valsartan shows maximum solubility in propylene glycol a non-volatile solvent. The IR studies ruled out any significant interaction betweenthe drug and excipients. The XRD analysis confirmed formation of a solid solution inside the compact matrix. SEM indicates that the drug was totallysolubilized in the LS system. The tableting properties of the LS compacts were within the acceptable limits. The release rates of LS compacts weremarkedly higher compared with directly compressed tablets due to increasing wetting properties and surface area of the drug.Conclusion: This study shows that the LS technique is a promising alternative tool for improvement of the dissolution rate of biopharmaceuticalclassification system Class II drug.Keywords: Dissolution rate, Liquisolid compact, Valsartan, Non-volatile solvents, Liquid load facto