A promising nanomatrix system of simvastatin for oral delivery: Evaluation in vitro and in vivo.

Because of the low solubility, the oral bioavailability of simvastatin (SV) was poor, which restricted the application in clinic. In order to increase the dissolution and the oral absorption of simvastatin, we prepared a novel solid nanomatrix of SV with pharmaceutical acceptable nano-sized silica and Eudragit®. The nanomatrix was prepared using solvent evaporate method and the formulation was optimized. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to analyze the physicochemical characterization of the SV nanomatrix. The results indicated that the SV existed in the nanomatrix was in a state of molecule or amorphous form. The optimal formulation, consisted of SV, Eudragit® L100-55 and Sylysia 350 (1:5:5, w/w/w), significantly enhanced the dissolution of SV compared with Zocor. And the relative bioavailability was 272% to Zocor. The oral absorption of simvastatin was enhanced markedly. The SV nanomatrix after storage for 1 year displayed similar performance in vitro and in vivo with the freshly prepared nanomatrix. The stability of SV nanomatrix achieved the desired objectives. In conclusion, the nanomatrix system described here had superior performance in vitro and in vivo and was expected to have a promising future as an alternative oral drug delivery system for SV.