RESUMEN
Heparin is a sulfated glycosaminoglycan (GAG), which contains N-acetylated or N-sulfated glucosamine (GlcN). Heparin, which is generally obtained from the healthy porcine intestines, is widely used as an anticoagulant during dialysis and treatments of thrombosis such as disseminated intravascular coagulation. Dermatan sulfate (DS) and chondroitin sulfate (CS), which are galactosamine (GalN)-containing GAGs, are major process-related impurities of heparin products. The varying DS and CS contents between heparin products can be responsible for the different anticoagulant activities of heparin. Therefore, a test to determine the concentrations of GalN-containing GAG is essential to ensure the quality and safety of heparin products. In this study, we developed a method for determination of relative content of GalN from GalN-containing GAG in heparin active pharmaceutical ingredients (APIs). The method validation and collaborative study with heparin manufacturers and suppliers showed that our method has enough specificity, sensitivity, linearity, repeatability, reproducibility, and recovery as the limiting test for GalN from GalN-containing GAGs. We believe that our method will be useful for ensuring quality, efficacy, and safety of pharmaceutical heparins. On July 30, 2010, the GalN limiting test based on our method was adopted in the heparin sodium monograph in the Japanese Pharmacopoeia.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Contaminación de Medicamentos/prevención & control , Galactosamina/análisis , Heparina/análisis , Sulfatos de Condroitina/análisis , Sulfatos de Condroitina/química , Dermatán Sulfato/análisis , Dermatán Sulfato/química , Colorantes Fluorescentes/química , Heparina/química , Hidrólisis , Modelos Químicos , Reproducibilidad de los Resultados , para-Aminobenzoatos/químicaRESUMEN
Heparin sodium and heparin calcium, which are widely used as anti-coagulants, are known to potentially contain the natural impurity dermatan sulfate (DS). Recently serious adverse events occurred in patients receiving heparin sodium in the US, and a contaminant oversulfated chondroitin sulfate (OSCS) was found to be a cause of the events. To ensure the quality and safety of pharmaceutical heparins, there is need of a physicochemical identification test that can discriminate heparin from the heparin-related substances as well as a sensitive purity test for OSCS. Recently, HPLC with a strong-anion exchange column was proposed as the methods for identifying heparin and determination of OSCS in heparin sodium. Although this method is convenient and easy to perform, the only column suitable for this purpose is the Dionex IonPac AS11-HC column. In this study, we developed alternative identification test and test for OSCS in both heparin sodium and heparin calcium using a weak anion-exchange column. The identification test allowed for separation of heparin from the impurity DS and contaminant OSCS in a shorter time. The purity test provided enough sensitivity, specificity, linearity, recovery and repeatability for OSCS. We believe that our methods will be useful for quality control of pharmaceutical heparins.
Asunto(s)
Sulfatos de Condroitina/aislamiento & purificación , Contaminación de Medicamentos , Heparina/análisis , Heparina/química , Resinas de Intercambio Aniónico/química , Sulfatos de Condroitina/análisis , Cromatografía Líquida de Alta Presión/métodos , Electroforesis Capilar/métodos , Heparina/aislamiento & purificaciónRESUMEN
We treated two patients suffering from intractable myasthenia gravis (MG) with low-dose tacrolimus plus prednisolone. Both patients showed significant improvement of myasthenic signs, accompanied by suppressed serum anti-acetylcholine receptor antibody, waning in compound muscle action potential by repetitive nerve stimulation and IL-2 production by peripheral blood mononuclear cells. Low-dose tacrolimus plus prednisolone is a promising therapeutic regimen for intractable MG.