Qualification of HSQC methods for quantitative composition of heparin and low molecular weight heparins
An NMR HSQC method has recently been proposed for the quantitative determination of the mono- and disaccharide subunits of heparin and low molecular weight heparins (LMWH). The focus of the current study was the validation of this procedure to make the 2D-NMR method suitable for pharmaceutical quality control applications. Pre-validation work investigated the effects of several experimental parameters to assess robustness and to optimize critical factors. Important experimental parameters were pulse sequence selection, equilibration interval between pulse trains and temperature. These observations were needed so that the NMR method was sufficiently understood to enable continuous improvement. A standard validation study on heparin then examined linearity, repeatability, intermediate precision and limits of detection and quantitation; selected validation parameters were also determined for LMWH.