The evaluation and determination of the size of the particles can be controlled by laser. Method which is use in determination of result of micronisation process is in compliance with European Pharmacopoeia monograph No. 2.9.31. The apparatus which can be applied to determinate particle size at Polfa Tarchomin S.A. is the Premier particle size analyzer type Mastersizer 3000 of Malvern. The laser analyzer use diffraction technology and delivers rapid, accurate particle size distributions wet and dry dispersions. Measuring over the nanometer to millimeter particle size ranges, it packs exceptional performance into the smallest of footprints, bringing operator-independent measurements that every user can rely on.