고체분산체를 이용한 발사르탄의 용출 특성 개선

Abstract

Valsartan, a drug for the treatment of cardiovascular disease, exhibited low bioavailability which should be caused by, at least in part, limited solubility at low pH. Therefore, the aim of this study was to investigate the effect of surfactant on the solubility of valsartan and improve the dissolution profiles of valsartan via the preparation of solid dispersion (SD). Among tested surfactants including micronized poloxamer 407, creomophor, solutol, SLS and tween 80, micronized poloxamer 407 appeared to be most effective to enhance the solubility of valsartan at low pH. Thus, SD of valsartan was prepared by using poloxamer 407. The dissolution profiles of SDs (Drug:poloxamer = 1:3 or 1:5) were not pH-dependent and they showed desirable dissolution profiles over the pH range of 1.2 to 7.0. The results of powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) indicated that the drug in SDs was in the amorphous form. In conclusion, SDs containing micronized Poloxamer 407 appeared to be useful for improving the dissolution rate as well as solubility of valsartan at low pH.