title: Pharmacokinetics of an oral extended-release formulation of doxycycline hyclate containing acrylic acid and polymethacrylate in dogs.
abstract: OBJECTIVE
  To determine the pharmacokinetics of doxycycline hyclate administered orally in the form of experimental formulations with different proportions of acrylic acid-polymethacrylate-based matrices.
  
  
  METHODS
  30 healthy adult dogs.
  
  
  METHODS
  In a crossover study, dogs were randomly assigned (in groups of 10) to receive a single oral dose (20 mg/kg) of doxycycline hyclate without excipients (control) or extended-release formulations (ERFs) containing doxycycline, acrylic acid polymer, and polymethacrylate in the following proportions: 1:0.5:0.0075 (ERF1) or 1:1:0.015 (ERF2). Serum concentrations of doxycycline were determined for pharmacokinetic analysis before and at several intervals after each treatment.
  
  
  RESULTS
  Following oral administration to the study dogs, each ERF resulted in therapeutic serum doxycycline concentrations for 48 hours, whereas the control treatment resulted in therapeutic serum doxycycline concentrations for only 24 hours. All pharmacokinetic parameters for ERF1 and ERF2 were significantly different; however, findings for ERF1 did not differ significantly from those for the control treatment.
  
  
  CONCLUSIONS
  Results indicated that both ERFs containing doxycycline, acrylic acid polymer, and polymethacrylate had an adequate pharmacokinetic-pharmacodynamic relationship for a time-dependent drug and a longer release time than doxycycline alone following oral administration in dogs. Given the minimum effective serum doxycycline concentration of 0.26 μg/mL, a dose interval of 48 hours can be achieved for each tested ERF. This minimum inhibitory concentration has the potential to be effective against several susceptible bacteria involved in important infections in dogs. Treatment of dogs with either ERF may have several benefits over treatment with doxycycline alone.
authors: Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Delegación Coyoacán, Ciudad de México C.P. 04510, México.
authors: Sara Melisa Arciniegas
authors: SM
authors: Ruiz
authors: Lilia Gutiérrez
authors: LG
authors: Olvera
authors: Sara del Carmen Caballero
authors: Sdel C
authors: Chacón
authors: Dinorah Vargas
authors: DV
authors: Estrada
mesh_terms: D000179:Acrylates; D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002626:Chemistry, Pharmaceutical; D018592:Cross-Over Studies; D004285:Dogs / Q000097:blood*; D004318:Doxycycline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D006207:Half-Life; D008297:Male; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D011109:Polymethacrylic Acids
chemical_list: D000179:Acrylates; D000900:Anti-Bacterial Agents; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; C036658:acrylic acid; D004318:Doxycycline