Article Text

Serum activity/concentration profiles of a sustained-released formulation of sulphathiazole-trimethoprim (2˙5:1) in calves
  1. H. Sumano, DVM, MD, PhD,
  2. L. Gutierrez, DVM, MSc1,
  3. M. A. Zamora, DVM2,
  4. M. Perez, DVM and
  5. C. Cruz, DVM3
  1. 1 Department of Physiology and Pharmacology, School of Veterinary Medicine, National Autonomous University of Mexico, Mexico City 04510, Mexico
  2. 2 PiSA Agropecuaria, Av España 1840, Guadalajara, Jalisco, Mexico
  3. 3 ‘La Montañeza’, Queretaro,Mexico


Thirty-six two-week-old healthy Holstein-Friesian calves weighing between 52 and 58 kg were divided at random into three groups of 12; group A calves were given a single oral bolus containing 2˙5 g sulphathiazole and 1 g trimethoprim in a sustained-release formulation; group B received the same doses of the drugs but the trimethoprim was not in a sustained-release formulation; group C received a bolus containing 2˙5 g sulphathiazole and 0˙5 g conventional trimethoprim. Blood samples were collected at intervals for two days, the serum was separated and the composite antibacterial activity profiles of the mixture were analysed by an agar-diffusion microbiological method. The mean maximum activities in the serum of the three groups were 23˙4 μg/ml in group A, 9˙25 μg/ml in group B and 8˙01 μg/ml in group C. The mean areas under the curves of the serum activity time curves were 838 μg/ml/hour in group A, 216 μg/ml/hour in group B and 182 μg/ml/hour in group C.

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.