A novel self-developed technique ultra-fine particle process system (UPPS) which is quite different from existing technology was employed to prepare microspheres for oral administration.

The obtained MT microspheres by UPPS were spheroidal solid particles in size of about 80-120 μm with good flowability, which were fit for tableting or capsulation.

The in vitro release behavior of the MT microspheres was similar with commercial sustained release tablet of metroprolol succinate, Betaloc®, and not affected by the different pH value of release medium indicating a stable release in the whole gastrointestinal tract.

The capability of UPPS was proved that preparing sustained-release microspheres in one simple and controllable step.

http://www.sciencedirect.com/science/article/pii/S003259101500385X