Comparison of cyclofructan-, cyclodextrin-, and polysaccharide-based chiral stationary phases for the separation of pharmaceuticals.

In this study, cyclofructan (CF)-, cyclodextrin (CD)-, and polysaccharide-based chiral stationary phases (CSPs) were exploited in high-performance liquid chromatography (HPLC) for the chiral separations of different clinically and pharmaceutically important compounds. In particular, R-naphthylethyl carbamate CF6 (RN-CF6), 3,5-dimethylphenyl carbamate CF7 (DMP-CF7), neutral beta cyclodextrin (ß-CD), 3,5-dimethylphenyl carbamate ß-CD (DMP-ß-CD), and cellulose tris-(3,5-dimethylphenylcarbamate) (Cellulose-Tris DMP) columns were utilized under isocratic elution. The performance of these CSPs as chiral separation media was evaluated by use of nine analytes: acidic, basic, and amphiprotic. A possible correlation between the functional groups of these analytes and the chiral-recognition ability of each chiral column was also examined. The enantioseparations were optimized by varying different parameters, such as mobile phase additives, column temperature, and flow rate. Finally, a comparison was made between all CSPs, and it was expressed in terms of resolution (RS), efficiency (N), selectivity (α), retention factors (k1', k2') and analysis time (tR1, tR2). It was observed that RN-CF6 was the most suitable and efficient CSP for the chiral separation of various types of analytes, including acids, primary and tertiary amines, alcohols, and many neutral compounds. It was the only CSP that provided baseline enantioseparation of thyroxine (RS = 1.6) and cetirizine (RS = 2.0).

Chiral selectors in CE: Recent development and applications (mid-2014 to mid-2016).

This report, which is a sequence of a series of reviews, records the most important chiral selectors (CSs) applied in CE. It highlights the CSs that were used during the period 2014 to mid-2016. In this review, method developments, validations, and pharmaceutical along with biomedical applications are presented. The different CSs include CDs, antibiotics, cyclofructants, linear and branched oligo- and polysaccharides, and polymeric surfactants. In addition, the advantages of these CSs, along with their chiral recognition mechanisms, and their performance, are discussed.