Preparation method of sustained-release microparticles

The invention provides sustained-release microparticles. According to the invention, a preparation method of the sustained-release microparticles is conducted at normal temperature or low temperature in a whole course, which is quite conducive to high-temperature sensitive drugs, in particular compositions which polymer matrixes prepared from protein, nucleic acid and peptide drugs. Compared with public technologies, the preparation method disclosed by the invention can keep bioactivity of active substances to the greatest extent in the entire technological process; meanwhile, the prepared sustained-release microparticles have an excellent sustained-release effect close to a zero level, and drug concentration is kept stable in a sustained-release period, so that shortcomings of microparticles, which are prepared by a conventional S/O/W (solid-in-oil-in-water) process which needs to prepare the drug microparticles in advance, that drug release fails to occur in an early stage while rapid drug release happens in a late stage are overcome; and moreover, the sustained-release microparticles are relatively high in drug loading ratio and drug entrapment efficiency.