Analysis of structural variability in pharmaceutical excipients using solid-state NMR spectroscopy.

Polysaccharide-based excipients comprise the majority of most solid dosage forms and can vary dramatically in terms of structural and functionally related properties. Analytical methods for characterizing these important formulation components are crucial. Solid-state NMR spectroscopy (SSNMR) can provide a wealth of information on these materials while offering the advantages of non-destructive sample preparation and selectivity.

Analysis of composition, molecular weight, and water content variations in sodium alginate using solid-state NMR spectroscopy.

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.

Relevance of rheological properties of sodium alginate in solution to calcium alginate gel properties.

The purpose of this study is to determine whether sodium alginate solutions' rheological parameters are meaningful relative to sodium alginate's use in the formulation of calcium alginate gels. Calcium alginate gels were prepared from six different grades of sodium alginate (FMC Biopolymer), one of which was available in ten batches. Cylindrical gel samples were prepared from each of the gels and subjected to compression to fracture on an Instron Universal Testing Machine, equipped with a 1-kN load cell, at a cross-head speed of 120 mm/min.

Rheological evaluation of inter-grade and inter-batch variability of sodium alginate.

Polymeric excipients are often the least well-characterized components of pharmaceutical formulations. The aim of this study was to facilitate the QbD approach to pharmaceutical manufacturing by evaluating the inter-grade and inter-batch variability of pharmaceutical-grade polymeric excipients. Sodium alginate, a widely used polymeric excipient, was selected for evaluation using appropriate rheological methods and test conditions.