Evaluation of the diffusion of corticosteroids between the distal interphalangeal joint and navicular bursa in horses.
OBJECTIVE
To determine whether clinically effective concentrations of methylprednisolone or triamcinolone can be achieved in the navicular bursa after injection of methylprednisolone acetate (MPA) or triamcinolone acetonide (TA) into the distal interphalangeal joint (DIPJ) and whether clinically effective concentrations of these drugs can be achieved in the DIPJ after injecting the navicular bursa with the same doses of MPA or TA.


METHODS
32 healthy horses.


METHODS
Horses in groups 1 through 4 received 40 mg of MPA in the DIPJ, 10 mg of TA in the DIPJ, 40 mg of MPA in the navicular bursa, and 10 mg of TA in the navicular bursa, respectively. Concentrations of corticosteroids that diffused into the adjacent synovial structure were determined.


RESULTS
For group 1, injection of MPA into the DIPJ yielded a mean +/- SD concentration of 0.24 +/- 0.072 microg of methylprednisolone/mL in the navicular bursa. For group 2, injection of TA into the DIPJ yielded 0.124 +/- 0.075 microg of triamcinolone/mL in the navicular bursa. For group 3, injection of MPA into the navicular bursa yielded 0.05 +/- 0.012 microg of methylprednisolone/mL in the DIPJ. For group 4, injection of TA into the navicular bursa yielded 0.091 +/- 0.026 microg of triamcinolone/mL in the DIPJ.


CONCLUSIONS
A clinically effective concentration of methylprednisolone or triamcinolone diffused between the DIPJ and navicular bursa after intra-articular or intrabursal injection, which would justify injection of the DIPJ with MPA or TA to ameliorate inflammation of the navicular bursa.
Pauwels
Frederik E
FE
Department of Large Animal Surgery, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
Schumacher
James
J
Castro
Fernando A
FA
Holder
Troy E
TE
Carroll
Roger C
RC
Sega
Gary A
GA
Rogers
Chris W
CW
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002061:Bursa, Synovial / Q000378:metabolism*; D004058:Diffusion; D005260:Female; D006736:Horses / Q000378:metabolism*; D007596:Joints / Q000378:metabolism*; D016014:Linear Models; D008775:Methylprednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D000077555:Methylprednisolone Acetate; D011897:Random Allocation; D052616:Solid Phase Extraction / Q000662:veterinary; D013582:Synovial Fluid / Q000378:metabolism; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000493:pharmacokinetics*
D000893:Anti-Inflammatory Agents; D000077555:Methylprednisolone Acetate; D014222:Triamcinolone Acetonide; D008775:Methylprednisolone