Poloxamer and gelucire solid dispersion prepared by solvent evaporation; an effective means for solubility enhancement of tinidazole

Abstract

Many BCS Class II and IV drugs possess high therapeutic potential but shows less bioavailability due to poor solubility. Hence present study is focused on improvement of solubility and dissolution rate of poorly soluble drug; tinidazole. Solid dispersion of tinidazole were prepared with gelucire and poloxamer using various methods; kneading, fusion and solvent evaporation. Formulations were evaluated by saturation solubility, drug content, in vitro dissolution rate, FTIR, DSC, XRD and stability study. Optimised solid dispersions of gelucire and poloxamer provided dissolution rates faster than that of pure drug. In vitro dissolution studies revealed that formulation batch Sg14 shows 94.43 percent drug release with a correlation coefficient (R²) of 0.949 and batch Sp14 shows 97.69 percent drug release with a correlation coefficient (R²) of 0.993. DSC study revealed that there was no interaction between drug and carrier whereas the XRD study of optimised formulation batches demonstrates that there was a significant decrease in crystallinity when compared with XRD pattern of pure drug tinidazole. Significant change in solubility and in vitro dissolution rate of tinidazole would be due to amorphous state maintained in the optimised formulation batches. Hence overall formulation and evaluation studies of present research work indicate that solid dispersion by solvent evaporation method is an effective means to improve the solubility of tinidazole.