STUDY ON THE RIFAMPICIN POLYLACTIC ACID MICROSPHERES FOR LUNG TARGETING

In this paper, the effects of different variables on the preparation of polylactic acid microspheres (PLA-MS ) were studied. The optimized preparation conditions of rifampicin polylactic acid microspheres (RFP-PLA-MS) were aquired through orthogonal test. The paddle method was used to study the drug release properties of RFP-PLA-MS. Stability of RFP-PLA-MS at different temperatures was also studied. Pharmacokinetic and tissue distribution of RFP-PLA-MS after intravenous administration were carried out in rabbits. The experiments revealed that the RFP-PLA-MS was regular in its morphology with a mean diameter of 9.00±4.08 μm.The drug loading was 160% and encapsulation efficiency was 31.9%. The release properties could be expressed by the following equation: Q=20.77+10.12T_1/2(γ=0.9892). The RFP-PLA-MS was stable after stored at 4℃ and room temperature under desiccated condition for three months. RFP-PLA-MS showed a combination of lung targeting and sustained drug release in experiments on rabbits.