Comparison of pharmacokinetics of glucosamine and synovial fluid levels following administration of glucosamine sulphate or glucosamine hydrochloride1

Summary 

Objective

To compare the pharmacokinetics of glucosamine and the synovial fluid levels attained following treatment with glucosamine sulphate or glucosamine hydrochloride in a large animal model at clinically relevant doses.

Methods

Eight adult female horses were used. Crystalline glucosamine sulphate (Dona^®) or glucosamine hydrochloride was administered at a dose of 20mg/kg by either intravenous (IV) injection or nasogastric (NG) intubation. Plasma samples were collected before dosing and at 5, 15, 30, 60, 120, 360, 480 and 720min after dosing. Synovial fluid samples were collected from the radiocarpal joints within 48h before dosing and at 1, 6 and 12h post-dosing. Glucosamine was assayed by Liquid Chromatography Electrospray Tandem Mass Spectrometry (LC-ESI/MS/MS).

Results

Plasma concentrations reached ∼50μg/mL after IV injection and ∼1μg/mL after NG administration of both types of glucosamine. The median oral bioavailability was 9.4% for glucosamine sulphate and 6.1% for glucosamine hydrochloride. Synovial fluid concentrations were significantly higher at 1 and 6h following oral treatment with glucosamine sulphate compared to glucosamine hydrochloride. Twelve hours following oral administration, glucosamine levels in the plasma and the synovial fluid were still significantly higher than baseline for the glucosamine sulphate preparation, but not for the hydrochloride preparation.

Conclusion

Following oral administration of a clinically recommended dose of glucosamine sulphate (Dona^®), significantly higher synovial fluid concentrations of glucosamine are attained, when compared to an equivalent dose of glucosamine hydrochloride. Whether this difference is translated into a therapeutic effect on the joint tissues remains to be elucidated.

Key words: Glucosamine, Cartilage, Osteoarthritis, Neutraceutical, Horse