Stability and Dissolution of Nimodipine Amorphous Solid Dispersion Using Copovidone and Crospovidone as Carriers

OBJECTIVE To investigate the dissolution and physical stability of the amorphous solid dispersion(ASD) containing a poorly soluble drug nimodipine(NMP), and to optimize the ratio binary carriers of adopted as to formulate the ASD.

METHODS Copovidone(PVPVA) and crospovidone(PVPP) were selected as the polymeric carriers to prepare NMP solid dispersions by spray drying. Extreme vertices mix design was used to design formulations. Differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscope, polarization microscope and powder X-ray diffraction analysis were conducted to investigate the physicochemical properties and physical stability of ASDs. In situ optical fiber technology was used to test in vitro dissolution behavior of ASDs and their tablets.

RESULTS When the drug loading of NMP ASD was 20%, with PVPVA content at 25% and PVPP content at 55%, it remained stable under accelerated conditions for 1 month. Compared with conventional tablets, the ASD tablets prepared by the spray-drying method exhibit faster tablet disintegration speed and higher drug dissolution rate.

CONCLUSION The combination of copovidone and crospovidone as the ASD carrier can achieve better physical stability of amorphous drug, and the prepared ASD tablets show shorter disintegration time and faster drug dissolution.