Microparticles are free spherical dust between 1 and 1000 microns made of synthetic, non-biodegradable, and non-biodegradable polymers. There are two types of microparticles: microcapsules and micro matrix. The main types of microparticles are magnetic microparticles, polymer microparticles, bio-adhesive microparticles, biodegradable polymer microparticles, synthetic polymer microparticles, floating microparticles, and radioactive microparticles. The advantage of microcarriers over nanoparticles is that they do not cross the 100 nm interstitium during lymphatic transport and therefore act locally. Toxic substances can be solidified in the form of micro-encapsulated and dried particles. Moreover, methods to characterize numerous physicochemical parameters like drug release, thermal properties, and particle size are introduced, along with new tests like in vitro leaching tests and floating tests.