Estudio de la cinética de eliminación de marbofloxacina y desarrollo de un modelo predictivo de residuos en aves de engorde en condiciones de temperaturas extremas de explotación estival e invernal

Abstract

In poultry farming, ambient temperature should be maintained in a range between 18 to 24 ° C, to avoid physiological changes, which modify the kinetic behavior of antimicrobial drugs used, and interfering with withdrawal time to generate a healthy food. With the purpose of evaluating pharmacokinetic differences of marbofloxacin, second generation fluoroquinolone, in different seasons of the year, and to elaborate a predictive model in broiler chickens that allows adjustments in the withdrawal time, its plasma and muscular disposition were studied.Broiler chickens (n = 345) were used, formed into lots of 5 individuals per time, divided into 6 groups, according to the route of administration (intravenous and oral), receiving each animal a 2 mg / kg single dose, in spring, summer and winter. Post-administration plasma and muscle samples were obtained at different times: 0.08 to 24 hours (intravenous) and 0.25 to 120 hours (oral). Samples were eluted by HPLC with fluorescence detector, with a linearity of r2≥0.99 and high percentages of recoverability and coefficients of variation ≤ 1.73. Plasma and muscle concentrations at different times were analyzed with an ANOVA and the PK Solution 2.0 software. Withdrawal time was determined by the Riviere and Sundlof equation, corroborated with the WT 1.4 software. Winter and summer plasma concentrations by oral route were lower (p <0.05) than in the control season (spring), and were detected in winter until 72 hours post-application. Differences in plasma pharmacokinetic parameters are presented orally with respect to the control group, with greater purification in summer, greater permanence in winter and lower oral bioavailability in summer and winter. In muscle, orally significantly higher concentrations were recorded (p <0.05) in winter compared to the other two periods, and it was detected up to 72 hours after application. The elimination half-life and TMR determine a later release of the drug in winter as opposed to spring. In summer, concentrations in muscle are reduced and drug withdrawal is rapid. The kinetics of elimination of marbofloxacin in chickens administered in different seasons of the year suffers variations; the elimination half-life is shortened in summer and extends in winter, determining a withdrawal time of 3 days for spring and 2 and 4 days for summer and winter respectively; what demands an adjustment according to the time, giving a healthy food for humanity.