Research on in vitro release of Isoniazid (INH) super paramagnetic microspheres in different magnetic fields.

To explore in vitro release rules of isoniazid (INH) when Isoniazid Super paramagnetic Iron Oxide Microspheres (ISPIOM) are subject to no external magnetic field, applied mechanical magnetic field and scillating magnetic field. ISPIOM was prepared by using the spray drying method; Isoniazid contented in the microspheres was determined, the drug loading capacity and encapsulation efficiency were calculated. Release of isoniazid in the microspheres was determined respectively under the effect of no external magnetic field, applied mechanical magnetic field and oscillating magnetic field, to explore the release rules. In solution with pH=7.4 PBS, microspheres featured 8-hour sustained release under the effect of magnetic field, the released rate of the microspheres is accelerated,. In solution with pH=3 PBS, microspheres release faster and could realize the fastest completion of release in 2 hours under the effect of oscillating magnetic field. To join the external magnetic field in different point time to can't affect the release, under pH=3 of medium, ISPIOM release faster; under the effect of magnetic field, the released rate of the microspheres is accelerated, and the longer effect of magnetic field, the faster release. Oscillating magnetic field can make ISPIOM within a certain period of time, get ideal release curve, so as to achieve good control release effect.