INVESTIGADORES
IMPERIALE Fernanda Andrea
artículos
Título:
A detailed assessment of the pattern of moxidectin tissue distribution after pour-on treatmant in calves
Autor/es:
SALLOVITZ, J.; LIFSCHITZ, A.; IMPERIALE, F.; VIRKEL, G.; LANUSSE, C.
Revista:
JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS
Editorial:
Blackwell Synergy
Referencias:
Año: 2003 p. 397 - 404
ISSN:
0140-7783
Resumen:
The use of topical (pour-on) administration of endectocide drugs in cattle has
reached world-wide acceptance. However, only limited information is available
on the kinetic behaviour for topically administered moxidectin (MXD). To
improve our understanding of the relationship between pharmacokinetics and
efficacy for pour-on preparations, MXD concentration profiles were measured in
tissues of endo- and ectoparasites location over 35 days postadministration.
MXD distribution to the fluid content and mucosal tissue of the abomasum and
different intestinal sections (duodenum, ileum, caecum and colon) was assessed.
The comparative patterns of MXD distribution to skin and hypodermic tissue
from different anatomical sites (backline, rib cage, thigh and face) were also
investigated following the pour-on administration. Wide tissue distribution and
long residence time characterized the kinetics of topically administered MXD.
MXD was recovered between 1 and 35 days post-treatment in all the tissues
investigated. The highest MXD availabilities were observed in the skin layers at
the site of administration (backline) and in the fat tissue. The fluid contents of
different intestinal sections showed MXD concentrations higher than those
measured in their respective mucosal tissues, particularly at day 1 posttreatment.
MXD concentrations in the skin (epidermis + dermis) were higher
than those measured in the hypodermic tissue. Large differences in the
availability of MXD in skin from different anatomical regions (backline > rib
cage > thigh > face) were observed. The low plasma and the high skin
availability indicate the formation of a skin depot of the drug, being released
slowly to the plasma and reaching concentrations in systemic tissues (abomasal
mucosa, lungs, etc.) similar to those measured after subcutaneous administration.
These findings demonstrate that target parasites may be exposed to
markedly different drug concentrations according to their location sites, which
is particularly relevant for ectoparasites located in different anatomical regions.
Knowledge of the tissue distribution of topically administered endectocides
contributes to understand the differences observed in efficacy and/or persistence
of activity and to optimize their use in cattle.