OBJECTIVE  To investigate the dissolution and physical stability of the amorphous solid dispersion(ASD) containing a poorly soluble drug nimodipine(NMP). The binary carriers of copovidione and crospovidone were adopted to formulate the ASD and the ratio of copovidoine to crospovidione was optimized.

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 NMP ASD drug loading was 20%, the contents of PVPVA and PVPP was 25% and 55% respectively, ASD remained physically stable during accelerated stability test. The prepared ASD tablets exhibited shorter disintegration rate and faster drug dissolution rate.

CONCLUSION  When copovidone alone is adopted as the ASD carrier, the ASD tablets have long disintegration time and slow drug dissolution; whereas if crospovidone is used as the carrier, the amorphous drug is not stable. 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.