Abstract: In order to provide the idea of confirming mixer parameters for enterprises using dry mixing process to produce formula food for special medical purposes. This test took the coefficient of variation as the index and drew a conclusion through single factor test: when the mixing time of three-dimensional mixer is 20 min,the mixing frequency is 30 Hz and the mixing amount is 2~3 kg,the coefficient of variation of vitamin D,vitamin E,vitamin B1,calcium and phosphorus is less than 5%,at the same time,it met the requirements of mixing uniformity in the dry mixing equipment in the GMP guidelines for drugs: oral solid preparations of the State Food and Drug Administration and the guidelines for sampling and evaluation of mixing uniformity of the U.S. Food and drug administration. Therefore,the optimal process parameters of the mixer in the dry mixing process of formula food for special medical purposes were determined.

Key words: food for special medical purpose, mixing uniformity, coefficient of variation