Water-soluble cyclodextrinpolymers for enhanced relative recovery of hydrophobic analytes during microdialysis sampling

Abstract

Microdialysis relative recovery (RR) enhancement using different water-soluble, epichlorohydrin-based cyclodextrin polymers (CD–EPS) was studied in vitro for different analytes, amitryptiline, carbamazepine, hydroquinone, ibuprofen, and 4-nitrophenol. When compared to the native CDs (α, β, and γ) on a per mole basis, the CD–EPS enhanced microdialysis RR was either statistically greater or the same. β-CD–EPS was more highly retained than native β-CD by a 20 000 Da molecular weight cutoff (MWCO) polycarbonate membrane, but showed no statistical difference for loss across a 100 000 Da MWCO polyethersulfone membrane (PES). When the same weight percent of β-CD or β-CD–EPS was included in the microdialysis perfusion fluid, the β-CD–EPS produced a higher microdialysis RR than native β-CD for all analytes across the PES membrane. However, enhancements for the PC membrane were statistically insignificant when β-CD and β-CD–EPS were compared on a per mole basis. These results suggest that CD–EPS may be used as effective enhancement agents during microdialysis sampling and for some membranes provide the additional advantage of being retained more than native CDs.