Enantiomeric resolution of doxazosin mesylate and its process-related substances on polysaccharide chiral stationary phases.
High-performance liquid chromatographic methods for separation of racemic doxazosin mesylate and its synthetic precursors on polysaccharide based stationary phases viz., amylose tris-(3,5-dimethylphenylcarbamate) (Chiralpak AD-H) and cellulose tris-(3,5-dimethylphenylcarbamate) (Chiralcel OD-H) were developed. The base line separation with Rs>1.50 was obtained using a mobile phase containing n-hexane-alcohol-0.1% diethylamine (ethanol, 1-propanol and 2-propanol) in various proportions. The effect of concentration of the alcoholic modifiers on the resolution was studied. A good separation was achieved on amylose based Chiralpak AD-H column when compared with cellulose based Chiralcel OD-H. The effects of structural features of the solutes and solvents on discrimination between the enantiomers were examined. The detection was carried out at 240 nm with UV detector while identification by polarimetric detector connected in series. The method was suitable not only for process development of doxazosin mesylate but also determination of enantiomeric purity of bulk drugs and pharmaceuticals.
Nageswara Rao
R
R
Analytical Chemistry Division, Discovery Laboratory, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, India. rnrao55@yahoo.com
Nagaraju
D
D
Narasa Raju
A
A
D000317:Adrenergic alpha-Antagonists / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D017292:Doxazosin / Q000032:analysis*; D011134:Polysaccharides / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013696:Temperature
D000317:Adrenergic alpha-Antagonists; D011134:Polysaccharides; D017292:Doxazosin