The quantification technique of powdered tylosin was validated. To this end, the technique recommended by the United States Pharmacopeia, 30th version, 2007 was standardized to adapt it to and to comply with the international regulations. The sample was composed of 10 % tylosin phosphate and 90 % Carrier 40-60. The agar diffusion was used to test the micro-organism Micrococcus luteus ATCC 9341