Nisoldipine is widely used clinically as an antihypertensive agent, however, its oral bioavailability and therapeutic effects are hindered by its very low solubility in water. The present study aimed to develop an amorphous solid dispersion (ASD) for nisoldipine, using hot melt extrusion, to increase or equilibrate with the in vitro dissolution and in vivo oral absorption of Nierxin, its commercial tablet formulation. The final preparation was prepared with Kollidon VA64 at a drug polymer weight ratio of 1:10. The amorphous state was confirmed by powder X-ray diffractometry, differential scanning calorimetry, and Fourier-transform infrared spectroscopy. This ASD exhibited a higher dissolution profile than Nierxin and its physical mixtures. It maintained an amorphous state when stored at 60 degrees C over 10 days, however, the hydrogen bonds between nisoldipine and Kollidon VA64 were disrupted and its dissolution slightly reduced when stored at RH 92.5% for 10 days. The pharmacokinetic study carried out in beagle dogs demonstrated that the ASD was bioequivalent to Nierxin. The results of this study suggest that ASD prepared by hot melt extrusion can be used as a suitable alternative to Nierxin in the future. (C) 2016 Elsevier B.V. All rights reserved.