Pharmacokinetics of intraarticular liposomal amphotericin B in goats (Capra aegagrus hircus)

Lameness is a significant welfare concern in goats. Amphotericin B is used via intraarticular (IA) administration in models to study experimentally induced lameness in large animals. The main objective of this study was to estimate plasma pharmacokinetic (PK) parameters for amphotericin B in goats after a single IA administration. Liposomal amphotericin B was administered to ten Kiko-cross goats at a dose of 10 mg total (range: 0.34-0.51 mg/kg) via IA administration into the right hind lateral distal interphalangeal joint. Plasma samples were collected over 96 h. Amphotericin B concentrations were measured via liquid chromatography/mass spectrometry (LC-MS/MS). A non-compartmental analysis was used to derive PK parameters. Following single IA administration, maximum plasma concentration was estimated at 54.6 +/- 16.5 ng/mL, and time to maximum concentration ranged from 6 to 12 h. Elimination half-life was estimated at 30.9 +/- 16.5 h, and mean residence time was 45.1 +/- 10.4 h. The volume of distribution after IA administration was 13.3 +/- 9.4 L/kg. The area under the curve was 1481 +/- 761 h*ng/mL. The achieved maximum concentration was less than the observed concentrations for other species and routes of administration. Further research is needed into the pharmacodynamics of IA liposomal amphotericin B in goats to determine specific research strategies.