Preparation of adriamycin magnetic gelatin microspheres and rudiment study of analgesic effect

Objective: To study preparation and characteristics of adriamycin（ADM） magnetic gelatin microspheres,and to investigate its analgesic effect.Methods: Adriamycin magnetic gelatin microspheres were prepared by emulsion-crosslinking.Twenty-eight rabbits were randomly divided into 5 groups sham operation group,gelatin microsphere controlled group（5 mg and 15 mg）,and adriamycin microsphere group（5 mg and 15 mg）.Under the effect of magnet,microspheres were infused into cavitas subarachnoidealis of rabbit.The pain threshold of electronic stimulates and motor function of rabbits’ hinder limbers were observed continuously.Results: The optimal ratio of adriamycin magnetic gelatin microsphere was 1∶15.The magneto-adsorption rate of the microspheres was 100%.The outline of microsphere was regular.The dispersivity and fluidity were perfect.The percent of drug release from adriamycin magnetic gelatin microspheres was over 90% during 2 hours.Adriamycin magnetic gelatin microsphere at dose of 15mg injected into subarachnoid space,caused obvious rise of pain threshold（P＜0.01）for more than 30 days,but not in motor function.Conclusion: The prepared adriamycin magnetic gelatin microsphere has good properties of drug-targeting and drug sustain releasing.It can cause the dissociation of kino-sense,so has obviously analgesic effect.