| Objective: To make a useful way in prepareing microspheres of PLGA containing cyclosporin and test efficacy of microspheres of PLGA containing cyclosporin A in the prevention of corneal allograft rejection in the rabbit.Methods: Microspheres of PLGA containing cyclosporin was prepared by a solvent evaporation and solvent extraction process, inspecting their shape, diameters and prepare conditions; the concentration of CsA in the aqueous was measured at 6, 12, 24, 48, 72 and 144 hours after injection microspheres of PLGA containing cyclosporin or cyclosporin solution to the normal rabbit eyes; we have observed survival time and rejection rate of grafts and durg reaction to the rabbits eyes respectively when using microspheres of PLGA and cyclosporin solution in the prevention of high risk corneal allograft rejection.Results: The shape of microspheres is even and round and the average of its diameters is 1.99 + 3.49um. The aqueous levels ranged from 112 + 2.58ug/L at 6 hours to 64 + 3.91ug/L at 144 hours in the CsA microspheres group, while in the CsA soultion group the quantity was undeceted by HPLC. Grafts mean survival time and rejection rates are 86.30 + 9.50 days and 20% in the group which usedmicrospheres of cyclosporin and in the other group they are 71.10 + 25.50days and 40%. There is significant difference in the mean survival time of grafts between two groups (P<0.1) , but there is no significant difference in the grafts rejection rates between two groups ((P>0.1) . Comparing two formulation , the group of microspheres had little drug reaction to the rabbit eyesConclusion: The microspheres is promising to be developed as a long-acting cyclosporin formulation. |
