Studies on lung targeting gelatin microspheres of mitoxantrone

Lung targeting gelatin microspheres of mitoxantrone(DHA)were prepared by atwo-step methed. The diameter of 87. 36%of the DHAQ gelatin microspheres (DHAQ-GMS)was inthe range of 5.1 to 25.0 μm. Release of the drug from the DHAQ-GMS in vitro became much slowerand its t1/2 was 4 times longer than that of pure DHAQ.The characteristic peak of heat absorption onthe differential thermal analysis curve was at 133℃ and almost no change was observed after theDHAQ-GMS were stored for 3 months at 37℃ (relative humidity 75%). The distribution test in vivoin mice indicated that the lung targeting effect of the DHAQ-GMS was obvious and that the targetingefficiency of the lung compared to other organs and blood increased 3 to 35 times, Kinetic behavior ofthe drug in mouse lung could be described by one open compartment model, and the average residual time increased by 10h.