Physico-chemical characterization and stability study of glassy simvastatin.

The objective of the present study was to investigate the glass forming capability of a model drug simvastatin. The glassy material produced by melt quench technique was subjected to physico-chemical characterization and subsequent stability and enthalpy relaxation study. The chemical stability of drug during preparation of glass was tested by High Performance Liquid Chromatography (HPLC) and Infrared (IR) spectroscopy. The presence of amorphous form was confirmed by DSC and XRPD. Surprisingly, glassy simvastatin was almost stable throughout the period of stability, inspite of its Tg being relatively low. The stability and very low enthalpy recovery of glassy simvastatin perhaps could be attributed to strong inter-molecular hydrogen bonding.