Quantitative determination of clenbuterol enantiomers in human plasma by high-performance liquid chromatography using the macrocyclic antibiotic chiral stationary phase teicoplanin.

We report a method for the high-performance liquid chromatographic (HPLC) chiral separation of racemic clenbuterol in human plasma. Human plasma was spiked with stock solutions of clenbuterol hydrochloride and practolol as the internal standard. Following a liquid-liquid extraction procedure with 10% (+/-)-2-butanol/isopropyl ether under alkaline conditions, the dried samples were reconstituted in methanol and chromatographed using a macrocyclic antibiotic chiral stationary phase (CSP) known as Chirobiotic T(trade mark) (teicoplanin).

Enantioselective separation of several piperidine-2, 6-diones on a covalently bonded cellulose 3,5-dimethylphenyl carbamate/10-undecenoate chiral selector.

A series of piperidine-2, 6-dione drugs were enantiomerically resolved on a covalently bonded cellulose 3,5-dimethylphenyl carbamate/10-undecenoate chiral stationary phase (CSP), under normal- or reversed-phase conditions. A single column that can be applied in both modes may be advantageous when considering the shorter setup time required and the solubility of the compound to be analysed since many samples possess different solubilities. The covalently bonded CSP was compared to a commercially available chiral adsorbent, Chiralcel OD, which was previously used in our laboratory for the enantiomeric resolution of the above-mentioned drug series.

Direct enantiomeric separation of cathinone and one major metabolite on cellobiohydrolase (CBH-I) chiral stationary phase.

A direct, isocratic high-performance liquid chromatographic (HPLC) method is described for the enantiomeric separation of racemic cathinone and one of its metabolites (+/-)-norephedrine, on a protein-based chiral stationary phase (CSP), cellobiohydrolase, known as CBH-I, under reversed-phase conditions. It was determined that the S-(-)-enantiomer eluted first for cathinone while the 1S,2R-(+)-enantiomer eluted first for norephedrine. The procedure is simple with no sample derivatization required and a short assay time.

Direct chiral resolution of phenylalkylamines using a crown ether chiral stationary phase.

A direct, isocratic high-performance liquid chromatographic method is described for the enantiomeric resolution of a number of phenylalkylamines, namely, racemic cathinone, amphetamine, norephedrine, and norphenylephrine, without sample derivatization. The separations were achieved on an S-18-crown-6-ether chiral stationary phase known as CR(+). The chromatographic parameters alpha (separation factor) and Rs (resolution factor) lay within a narrow range for all compounds used in this study except for cathinone, which resulted in high alpha and Rs values.

Direct separation of tranylcypromine enantiomers and their profile in an atypical depressive patient.

An isocratic and simple high-performance liquid chromatographic method is developed for the direct resolution of the tranylcypromine (TCP) enantiomers. The method involves the use of an S-18-crown-6-ether chiral stationary phase known as the Crownpak CR (+) column. The stereochemical separation factor (alpha) obtained was 1.