The present invention provides a method for producing particles having a reduced particle size distribution, which method comprises the steps of: a) providing a composition comprising particles； b) subjecting the particles in said composition to a size reduction step or to a size growth step； c) feeding said particles to a first membrane separation system to separate said particles according to size； d) recycling those particles that do not meet the size criteria back to step a)； e) optionally, collecting in a collection tank the permeate of the first membrane separation system. Particles obtainable according to the method of the invention and characterized by having a near monodisperse particle size distribution are also provided. The particles are preferably characterized by having a particle size distribution with a span of less than 2.0. The invention also provides pharmaceutical compositions comprising particles according to the invention, and also apparatus for carrying out the method of the invention.本發明提供一種用於生產粒徑分佈減小之粒子的方法，該方法包含以下步驟：a)提供包含粒子之組合物；b)對該組合物中之該等粒子進行尺寸減小步驟或尺寸增長步驟；c)將該等粒子饋送至第一膜分離系統以根據尺寸分離該等粒子；d)使不滿足尺寸標準之彼等粒子再循環返回至步驟a)；e)視情況，在收集槽中收集該第一膜分離系統之滲透物。亦提供可根據本發明方法獲得且特徵為具有幾近單分散之粒徑分佈的粒子。該等粒子較佳特徵為具有跨距小於2.0之粒徑分佈。本發明亦提供包含本發明粒子之醫藥組合物以及用於進行本發明方法之設備。
