AIMTo establish new methods for the chiral separation and preparation of three new drugs, alfuzosin, terazosin and doxazosin.

METHODSBy optimizing factors which affect the chiral separation, modifier of solvent, chiral additive, pH of mobile phase, modifier of organic base and stationary phase, the optimum condition for chiral separation were selected. The preparation of enantiomers was carried out on semi-preparative reverse phase column (7.8 mm x 250 mm C4 5 microns). Acetonitrile-water modified by the addition of carboxymethyl-beta-cyclodextrin (2%-5%, w/v) was applied as chiral mobile phase.

RESULTSThe enantiomers of three new drugs were base-line-separated and milligram-scale samples of enantiomer were obtained.

CONCLUSIONThe newly established method can be used in research and development of the enantiomers of three new drugs.

Adrenergic alpha-1 Receptor Antagonists ; Adrenergic alpha-Antagonists ; isolation & purification ; Chromatography, High Pressure Liquid ; methods ; Doxazosin ; isolation & purification ; Molecular Structure ; Prazosin ; analogs & derivatives ; isolation & purification ; Quinazolines ; isolation & purification

OBJECTIVE: To develop a specific, sensitive, reproducible SPE-HPLC method for the determination of 37 drugs in whole blood. METHODS: With the doxapram as internal standard, Oasis column was used to extract drugs from whole blood. Two kinds of mobile phases were used in this study. Separations were achieved by a LiChrospher 100 RP-C18 (250 mm x 4.0 mm x 5 microm) column kept at 50 degrees C, the DAD detector was set at 230 nm and 250 nm. RESULTS: The limit of detection were 1-30 ng/mL. The method showed excellent linearity and the linear correlation coefficient was > or =0.997 98. The relative standard deviation for between-day and within-day assay were <10%. CONCLUSION The method is effective, simple, reliable and has been used in real cases.
Chromatography, High Pressure Liquid/methods* ; Doxapram/isolation & purification* ; Doxepin/isolation & purification* ; Estazolam/isolation & purification* ; Forensic Medicine ; Humans ; Morphine/isolation & purification* ; Papaverine/isolation & purification* ; Pharmaceutical Preparations/isolation & purification* ; Prazosin/isolation & purification* ; Procaine/isolation & purification* ; Reproducibility of Results ; Sensitivity and Specificity ; Solid Phase Extraction/methods* ; Solvents/chemistry*