Development and validation of method for the simultaneous determination of sulfamethazine, trimethoprim and doxycycline in veterinary formulation using high performance liquid chromatography.

Sulfamethazine (SMZ), trimethoprim (TMP) and doxycycline (DOXY) are drugs of choice used in the treatment of intestinal and respiratory infections that affect poultry and swine. The aim of this study was develop and validate a simple, sensitive and fast method for the simultaneous determination of SMZ, TMP and DOXY in veterinary formulations by high-performance liquid chromatography. The separation was performed on a Macherey-Nagel C analytical column (4 × 125 mm, 5 μm), with a flow rate of 0.