Tetracycline class of antibiotics. 

Doxycycline through reversible with receptors on the bacterial ribosome 30 s subunit, interference tRNA and mRNA ribosome complex formation, prevent the peptide chain extension and inhibition of protein synthesis, so that the growth of bacteria quickly suppressed. Doxycycline inhibited both Gram-positive and Gram-negative bacteria. The bacteria were cross-resistant to doxycycline and oxytetracycline.

Internal and absorb quickly, less affected by food, high bioavailability, organization high penetrability, widely distributed, the effective blood drug concentration to maintain a long time. Pigs protein binding rate of 93%.