title: Analysis of composition, molecular weight, and water content variations in sodium alginate using solid-state NMR spectroscopy.
abstract: Solid-state nuclear magnetic resonance (SSNMR) spectroscopy has become more prevalent in the pharmaceutical industry due to its nondestructive nature and the wealth of information it can provide on a wide variety of solid samples. In this study, SSNMR spectra and relaxation times were used to analyze differences in monomer composition, molecular weight (MW), and water content among various sodium alginate samples. Differences in structure could be determined via spectral deconvolution of SSNMR spectra, and differences in intrinsic viscosity, MW, and water content were found to correlate to SSNMR relaxation times. The technique was found to be selective and sensitive enough to detect these changes in sodium alginate even when diluted with another excipient and compressed into a tablet.
authors: Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047.
authors: Diana M
authors: DM
authors: Sperger
authors: Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282.
authors: Shao
authors: S
authors: Fu
authors: Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282.
authors: Lawrence H
authors: LH
authors: Block
authors: Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536. Electronic address: eric.munson@uky.edu.
authors: Eric J
authors: EJ
authors: Munson
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002118:Calcium / Q000032:analysis; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005079:Excipients / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D044367:Phase Transition; D013607:Tablets; D013678:Technology, Pharmaceutical / Q000379:methods* / Q000592:standards; D013818:Thermogravimetry; D014783:Viscosity; D014867:Water / Q000032:analysis*
chemical_list: D000464:Alginates; D005079:Excipients; D006603:Hexuronic Acids; D013607:Tablets; D014867:Water; D020723:Glucuronic Acid; D002118:Calcium