An enzyme- linked immunosorbent assay for heparan sulfate proteoglycans

Simultaneous determination of chondroitin sulfate sodium, allantoin and pyridoxine hydrochloride in pharmaceutical eye drops by an ion-pair high-performance liquid chromatography

An ion-pair high-performance liquid chromatography (HPLC) method has been developed for the simultaneous determination of chondroitin sulfate sodium (CSS), allantoin and pyridoxine hydrochloride (VB(6)) in a commercial eye drops dosage form. An Alltima C(18) column (250 mm x 4.6 mm i.d., 5 microm) was used for the separation at room temperature, with 25 mM ammonium dihydrogen phosphate (containing 0.01% heptanesulfonic acid sodium salt) and acetonitrile (95:5, v/v) as the mobile phase at the flow rate of 0.5 mL min(-1). The detection wavelength for CSS, allantoin and VB(6) was 195 nm, 215 nm and 291 nm, respectively. The method showed good linearity for CSS, allantoin and VB(6), with correlation coefficients greater than 0.9996, in the range of 203.96-815.84 mg L(-1), 371.16-1488.64 mg L(-1), and 23.32-93.28 mg L(-1), respectively. The instrumental and method precisions were adequate with all relative standard deviations lower than 2.0%. The accuracy of this method, measured by the recovery of three compounds from spiked placebo solutions, was from 99.01% to 101.92%. The three components, CSS, allantoin and VB(6) were well separated from other ingredients and degradation products. This method is fast, simple, and can be used for direct and simultaneous determination of CSS, allantoin and VB(6) in the pharmaceutical preparation.

Solid phase assays in glycoconjugate research: applications to the analysis of proteoglycans, glycosaminoglycans and metalloproteinases

Glycoconjugates are a class of macromolecules consisting of different constituents, one of which is sugar moieties. Glycoconjugates comprise the majority of tissue constituents, both intracellular and extracellular. Extracellular glycoconjugates (glycoproteins and proteoglycans) participate in a wide variety of interactions, through which they maintain tissue integrity. Therefore, their analysis or the study of their possible interactions would give evidence for the state of tissues. Since the amounts of some of the extracellular glycoconjugates are usually low or the amounts of tissue to be examined come from biopsies, specific analytical systems are developed for their study, the most familiar being solid phase assays, which have the advantages of analysis of multiple samples on the same time, cheap instrumentation and high specificity.

A size-exclusion HPLC method for the determination of sodium chondroitin sulfate in pharmaceutical preparations

A size-exclusion HPLC method for the determination of sodium chondroitin sulfate (SCS) in pharmaceutical preparations has been developed and validated. The most important feature of this method compared with the previously reported assay methods was improved economical and determinative applications through direct analysis of SCS from pharmaceuticals. The linearity, precision, specificity, and accuracy of the method were established and validated. The intra- and inter-day precision was satisfactory with relative standard deviation lower than 1.0%. The recovery of SCS from multi-components pharmaceutical preparations were from 93.38 to 100.46%. Comparing our HPLC assay results with classical spectrophotometric methods, the developed method was considerably easy, simple and reproducible. As a result, the present method was supposed to be successfully applied to the assay of SCS for the routine quality control in pharmaceutical preparations.

Isolation and separation of proteoglycans

Proteoglycans contain a polypeptide core and an oligosaccharide chain composed of aminohexoses and uronic acid. The glycan chain is attached to the polypeptide in a bond to serine hydroxyl. The glycan chains may contain up to 200 disaccharide units and the proteoglycan molecular mass ranges from a few thousands to millions. Their physiological functions are related to barriers limiting diffusion across the membranes, articular lubrification, blood coagulation and cellular adhesion. The tissue proteoglycans can be extracted with 4 M guanidine hydrochloride and purified with chromatographic techniques. The soluble proteoglycans can be precipitated with cetylpyridinium chloride, purified by chromatography or by dialysis. All proteoglycan species are amenable to electrophoresis on polyacrylamide gels, and after blotting on polyvinylidene fluoride membranes, they can be stained for glycans. Proteoglycan analyses have shown their value in clinical mucopolysaccharidosis diagnostics, in occupational toxicology and in coagulation studies. Experimental applications include cell adhesion studies in tumor biology, regeneration in neurosciences or maturation of skin and kidneys.