Solubility Enhancement of Etoricoxib by Solid Dispersions Prepared by Spray Drying Technique

Abstract:

Many potent drugs inspite of their therapeutic efficacy are being shelved because of their poor biopharmaceutical properties. Physical transformation of such drugs from crystalline form to its more soluble amorphous form is one of the approaches for improving solubility. Present study utilizes the spray drying technique for physical transformation of a prototype poorly water-soluble drug, etoricoxib. Though metastable amorphous form of etoricoxib exhibited better solubility characteristics, its stabilization remains a challenge. Hence, solid dispersions of etoricoxib with non-ionic surfactant as poloxamer-407 and lipid carrier as gelucire-50/ were formulated by spray drying technique and subjected 13 to initial characterization to reveal drug content, saturation solubility, dissolution rate, morphological appearances, crystallinity, molecular interactions and residual solvent content. During initial characterization, all the proportions of etoricoxib solid dispersions reported enhanced saturation solubility and dissolution rate and only optimized proportions, decided on the basis of least crystallinity, were subjected to stability study. During stability study, the solubility characteristics of amorphous etoricoxib dropped drastically, but there was an insignificant decrease in those of the solid dispersions. The study thus reveals tremendous potential of solid dispersions of poorly water-soluble drug with poloxamer-407 and gelucire-50/ to enhance its stability and hence solubility. 13

Keywords: Etoricoxib, solubility enhancement, spray drying, solid dispersions