Further advances in identification of pentosan polysulfate monosaccharide composition by NMR

• Published in: Journal of pharmaceutical and biomedical analysis 2023-10, Vol.235, p.115672-115672, Article 115672
• Main Authors: Eisele, Giorgio, Alekseeva, Anna, Bertini, Sabrina, Gardini, Cristina, Paganini, Davide, Fonseca, Elizabeth Carolina Montatixe, Guerrini, Marco, Naggi, Annamaria
• Format: Article
• Language: English
• Subjects: 4-O-methyl-glucuronic acid; Monosaccharide composition; Pentosan polysulfate; Quality attributes; Quantitative HSQC NMR; Sulfated polysaccharide
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2023.115672

Several publications have recently proposed NMR spectroscopy to evaluate the critical quality attributes (CQA) of pentosan polysulfate sodium (PPS), the active ingredient of Elmiron™ approved to treat interstitial cystitis. PPS is a polymer of sulfated β(1—4)‐d‐xylopyranose residues randomly substituted by 4–O-methyl-glucopyranosyluronic acid, containing, beyond the main xylose-2,3-O-disulfate repetitive unit, some minor residues that can be marker of both the starting material and preparation process. In the present study we assigned some previously unknown cross-peaks in 1H–13C HSQC NMR of PPS related to its minor sequences adding additional details to its CQA. Four anomeric cross-peaks related to glucuronate-branched xylose and different sulfation pattern as well as the preceding xyloses were identified. Two minor process-related signals of monosulfated xyloses (unsubstituted in position 2 or 3) were also assigned. The isolation of a disaccharide fraction allowed the assignment of the reducing end xylose-α/β as well as the preceding xylose residues to be corrected. Additionally, the oversulfation of PPS allowed detection of the reducing end xylose-tri-1,2,3-O-sulfate. The newly identified cross-peaks were integrated into an updated quantitative NMR method. Finally, we demonstrated that an in-depth PPS analysis can be obtained using NMR instruments at medium magnetic fields (500 MHz/600 MHz), commonly available in pharmaceutical industries. [Display omitted] •Updated structural characterization of the complex drug Pentosan Polysulfate PPS.•Assignment of previously unknown resonances in HSQC NMR spectra of Elmiron® PPS.•Improved NMR analysis of the PPS monosaccharide composition and method validation.