Bioequivalence study of 500 mg glucosamine sulfate in Thai healthy volunteers

Glucosamine sulfate is widely used to relieve symptoms from osteoarthritis. The present study was conducted in order to determine pharmacokinetic and assess the in-vivo bioequivalence of two different hard capsule formulations of glucosamine sulfate when administered as equal dose of 500 mg. The two formulations contained different salt form where reference product is NaCl and test product is KCl.

A randomized, single dose, two-treatment, two-period, two-sequence crossover study was conducted. Twenty-four healthy volunteers were recruited at Siriraj Clinical Research Unit. Each subject received a dose of 500 mg glucosamine sulfate of both formulations with at least one-week washout period. Blood samples were collected over 24 h after the oral administration. The plasma fractions were analyzed for glucosamine using a liquid chromatography-mass spectrometry (LC-MS/MS).

Twenty-four volunteers were enrolled in the present study Pharmacokinetic parameters were determined using the non-compartment model. The 90% confidence intervals of the mean ratios (test/reference) of C(max) (93.69%; ranged from 86.68%-113.32%) and AUC(0-t), (97.73; ranged from 87.38%-112.62%) fell within the acceptable range (80-125%) for bioequivalent eligibility. Both preparations were well tolerated and had a few non-serious adverse events.

The glucosamine sulfate containing KCl (test product) is bioequivalent to glucosamine sulfate containing NaCl (reference product) in terms of rate and extent of absorption.