ChiraDex® (5 µm)

ChiraDex® (5 µm) HPLC Columns

Merck offers a broad range of HPLC columns that are fully compliant with USP (United States Pharmacopoeia) specifications. L45 USP columns are described as beta-cyclodextrin bonded to porous silica particles, 5 to 10 µm in diameter. ChiraDex® (5 µm) is an extremely versatile HPLC column with broad enantioselectivity that fulfills all L45 USP requirements.

The Versatile Column for Enantiomer Analysis

Optimized for chiral separations, ChiraDex® HPLC columns allow reliable determination of enantiomeric purity, and efficient isolation of pure enantiomers. This makes them extremely valuable for analyzing the pharmacological effects of chiral compounds in biological systems. Among many important pharmaceutical applications, ChiraDex® columns enable rapid enantiomer separation in the analysis of chiral drugs or flavor ingredients. The columns are suitable for chiral separations of numerous classes of compounds, including hydrocarbons, steroids, phenyl esters, aromatic amines, and heterocycles with 5 to 7-membered rings. Simply composed RP-eluents can be used in most separations.

Feature and Benefits

• Classified as L45 USP column
• Optimized for rapid, efficient chiral separations
• Suitable for numerous classes of chiral compounds
• Compatible with simple RP-eluents

Characterization of ChiraDex®

ChiraDex® columns are based on beta-cyclodextrin covalently linked to spherical silica particles. Cyclodextrins are cyclic oligosaccharides consisting of alpha-1,4-glycosidically-linked D-glucose units. Accordingly, beta-cyclodextrin consists of 7 glucose units. Geometrically seen, cyclodextrins are truncated cones with secondary hydroxy groups directed towards the larger opening, and primary hydroxy groups forming the smaller opening. This results in a hydrophobic inner cavity, contrasting with the two hydrophilic openings. Since cyclodextrins are made of chiral D-glucose units, their structure acts as a chiral selector. Due to their opposing configurations, the enantiomers of a racemic mixture can bond (to different degrees) with the cyclodextrin molecule. Thus, diastereomeric "inclusion complexes" are formed, based on hydrophobic interaction (between cavity and guest molecule), and stereo selective hydrogen bonds (between the C2 and C3 hydrogen groups of glucose molecules and the guest molecule).

Application Example

Separation of Cromakalim

Separation of Methadone

Specifications

Sorbent Characteristics	Silica particles with covalently bonded beta-cyclodextrin
Particle Shape	Spherical
Particle Size	5 μm
Pore Size	100 Å (10 nm)
Spec. Surface Area	300-360 m2/g
Chiral Selector	Beta-cyclodextrin
pH Range	pH 3 - 7.5
Shipping Eluent	Methanol/Water

Benefits of Enantiomers for Therapeutic Use