The Preparation And Characteristics Of Polyactic-co-glycolic Acid Morphine Microspheres

In this paper ,we selected morphine as a model drug ,and we used Polyactic-co-glycolic acid (PLGA) as carriers to make a biogradable and biocompatible microspheres(MS) to prolong the angelsia of morphine. We also studied the drug release in vitro, pharmacodynamics and biocompatibility in rats of morphine-MS in this paper.Objective: to study the preparation and characteristics of Morphine-PLGA Microspheres . Method : Morphine-PLGA Microspheres were prepared by emulsion-crosslinking method , and were observed by super-microscope. The content of morphine in the microspheres was measured by high performance liquid chromatography (HPLC). The regularity of the drug-releasing of this microspheres was measured also. The microspheres were also injected to rats to study the maintainess time of analgesia and biocompatible of this drug. Results: the Morphine-PLGA Microspheres were white powders and they were globular when observed in the super-microscope. The content of morphine in the microspheres is 11.86%,and the ratio of drug envelopment is 33% .the releasing test in vitro showed that the releasing time of the morphine can maintain 10 days. But Results of phamacodynamics in rats showed morphine-PLGA Microspheres could prolonged the time of analgesia to about 6 hours. In the biocompatibility study ,micrographs of pathological section of muscle after injection showed that this microspheres were biocompatible. Conclusion : Morphine-PLGA Microspheres are biocompatible and it can prolong the analgesia time of morphine ,but time it maintained did not reach the aim we preparaed. So the method to make this microspheres should be changed.