NIFEDIPINE AND FELODIPINE RELEASE FROM ETHYL CELLULOSE MICROSPHERES WITH UNIFORM SIZE AND SIZE DISTRIBUTION

摘要

The release profiles of nifedipine and felodipine, two well-known drugs for hypertension, were investigated using ethyl cellulose (EC) microspheres of different sizes as the delivery vehicles. The drugloaded microspheres with uniform size and size distribution were fabricated using the acoustic excitation method we previously reported. The drugs were homogeneously distributed in 25-μm-diameter microspheres but more concentrated on the surface in larger particles. The release profiles from 25-μmdiameter microspheres exhibited zero-order release without initial burst but low total percent release (7～10%) during the first 24 hours.