Preparation of Veterinary Premix with Dual Active Ingredients in Granular Form

The aim of the study was to investigate the preparation of granular veterinary premix containing two different antibiotics by fluid bed granulation process. The particle size and density of the active ingredients were investigated for the proper selection of the filler material. The used antibiotics were tylosin tartarate and colistin sulfate, while isomalt sugar alcohol and cellulose materials were selected as filler and binder, respectively. The colistin sulfate was fed together with the binder solution because of its low density, fine particle size and relatively low (1.2%) concentration in the product. The type and concentration of the binder in its solution, the feeding rate and the total amount of added binder solution were optimized for obtaining dust free granules with desirable abrasion resistance and good flowability. The active ingredient content for both antibiotics was preserved even at the elevated temperature applied during the fluid granulation process.