Clearly, understanding the mechanism of action for cyclodextrins and consequently finding the most appropriate canditate for the treatment of Niemann Pick C is one of the biggest challenges of our small society nowadays. However, when it comes to development, supporting analytical tools should be just as fine as understanding of the underlying mechanism. And for cyclodextrins, this may pose a real difficulty to handle. Still, we need to bear with it, since we know the differences of commercial cyclodextrins, even differences within pharma grade HPBCD from different manufacturers, that should not be neglected.
Of course, for HPBCD, there are pharmacopeial monographs (EP, USP), yet for instance, these do not contain an assay method. So how do you actually determine the HPBCD content in a blood or urine sample then? And if the lead would be another cyclodextrin, there is probably no “official” support to aid the development.
Back in the early days of this success story, Szemán et al made pioneer work in the Quantitative Determination of Hydroxypropylbetadex in Cerebrospinal Fluid of Children with Niemann-Pick type C disease after Intrathecal and Intracerebral Administration. Very recently, a new methodology, based on high resolution liquid chromatography with light scattering detector, has been applied to analyze Hydroxypropyl-beta-Cyclodextrin (HPβCD) in urine samples of a child affected by Niemann-Pick Type C disease.
What do you think is or would be the best way to analyze CDs in NPC samples? Is the current pharmacopeial method suitable for assay testing or would you have other recommendations?
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