Comparison of intravenous and oral meloxicam pharmacokinetics in female and male saanen goats

Abstract

This study aimed to investigate the effect of gender on the pharmacokinetics of meloxicam in goats following intravenous (IV, 0.5 mg/kg) and oral (PO, 1.0 mg/kg) administration. A crossover design was used with 12 clinically healthy Saanen goats (six females and six males). Plasma samples were collected up to 96 h post-administration and analyzed with an HPLC for meloxicam concentrations. Pharmacokinetic parameters were calculated and statistically compared between genders and administration routes. The results show that male goats exhibited significantly longer terminal half-life (T1/2λz ), a greater mean residence time (MRT0–∞), and higher systemic exposure (AUC0–∞) than females, particularly after oral administration. Oral bioavailability was calculated as 77.43% in females and 104.73% in males. These differences may be linked to gender-based variations in hepatic metabolism, enterohepatic recirculation, and the hormone-mediated modulation of cytochrome P450 activity. The findings are consistent with previous research demonstrating that gender can influence drug disposition through hormonal and enzymatic mechanisms. This study underscores the importance of considering gender as a biological variable in pharmacokinetic assessments of veterinary drugs, especially those used in food-producing animals, to optimize dosing strategies and ensure both therapeutic efficacy and food safety.