RESUMO
We prepared the isosorbide-5-mononitrate pulsatile controlled-release pellets (PCRP) and studied the influencing factors in vitro. The isosorbide-5-mononitrate (5-ISMN) pellets prepared by extrusion-spheronization technology were coated with swelling material as the inner coating swelling layer, and with ethylcellulose aqueous dispersion as the outer coating controlled layer. The influences of the coating materials of the swelling layer, the coating levels of the swelling layer and controlled layer,and the pH values of the media on the release of 5-ISMN from PCRP were investigated. The drug release from the pellets was pulsatile. The ISMN-5-PCRP, with a lag time of 5 h and more than 80% released within the following 1.5 h,were prepared by using the low-substituted hydroxypropyl cellulose as the inner swelling layer with 15% (weight) in coating thickness, and the ethylcellulose aqueous dispersion as the outer controlling layer with 13% (weight) in coating thickness.