Pravit Akarasereenont, Somruedee Chatsiricharoenkul and Piyapat Pongnarin
Glucosamine sulfate is widely used to relieve symptoms from osteoarthritis. This study was conducted in order to determine pharmacokinetic and assessed the in-vivo bioequivalence of two different hard capsule formulations of glucosamine sulfate when administered as equal dose of 1,500 mg. The two formulations contain 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-six healthy volunteers were recruited at Siriraj Clinical Research Unit. Each subject received a dose of 1,500 mg glucosamine sulfate of both formulations with at least a week washout period. Blood samples were collected over 24 hrs after the oral administration. The plasma fractions were analyzed for glucosamine using LC-MS/MS. Twenty-six volunteers 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 Cmax (111.19%; ranged from 93.01%-132.92%) and AUC0-t (107.24; ranged from 87.16%-131.93%) was not contained within the equivalence criteria of 80.00-125.00% (USFDA, 2003). However, this study showed the high intra-individual CV calculated from ANOVA for Cmax and AUC0-24 (≥ 30%). Thus, based on equivalence limits of USFDA (2003), the test product is not bioequivalent to the reference product in terms of rate and extent of absorption. However, concerning the wider equivalence criteria for highly variable drug (EMEA, 2008), the test product is bioequivalent to the reference formulation in terms of rate and extent of absorption.