Dietary supplements with glucosamine are one of the most popular over-the-counter products that are widely used all over the world for relieving symptoms of osteoarthritis.
Glucosamine (2-amino-2-deoxy-glucose), deriving from the natural amino monosaccharide, is an essential component of glycosaminoglycans in the articular cartilage and synovial fluid. Numerous studies have demonstrated that administration of glucosamine can relieve osteoarthritis symptoms and restore articular functions by stimulating the synthesis of proteoglycans and protecting articular cartilage. Therefore, glucosamine is recommended for the management of osteoarthritis by several guidelines from international societies and agencies like the Osteoarthritis Research Society International.
Glucosamine is found in the form of glucosamine hydrochloride (GlcN×HCl), glucosamine sulphate ((GlcN)2SO4), glucosamine sulphate potassium chloride ((GlcN)2SO4×2KCl) and N-acetylglucosamine (GlcNAc). Usually it is combined with other nutraceuticals such as chondroitin sulphate and methylsulfonylmethane. Even though glucosamine dietary supplements are sold worldwide, their production is poorly regulated. Considering that there are various glucosamine products available on the market and the current quality control of dietary supplements lacks regulations, there is a need for quantification of glucosamine content in these products.
According to U.S. Pharmacopeia glucosamine supplements should contain 90-110% of the label claim. The results from various studies demonstrated that about 30% of tested products failed to meet this acceptance criterion. The out of the specification results can be explained by less stringent quality control in the dietary supplement industry compared to pharmaceutical industry. Therefore, quality control of glucosamine in commercial products is of great importance and manufacturers should improve their quality control processes.
The main challenges in glucosamine analysis are the lack of chromophore and its high polarity. Glucosamine is usually analyzed by high-performance liquid chromatography (HPLC) with or without derivatization, which is by far the most widely used technique for routine analysis because of its sensitivity, selectivity, speed and the possibility for simultaneous determination of other analytes in tested products. In our laboratory we routinely perform direct quantitative determination of glucosamine in raw materials and commercial dietary supplements according to the current analytical trends and guidelines by validated HPLC method with high accuracy and precision. The method is suitable for convenient quality control in the growing dietary supplement market.
Many more dietary supplement assays are available. If you require a specific assay contact us: info@inslab.si.