Micellar electrokinetic chromatography for simultaneous determination of six corticosteroids in commercial pharmaceuticals.
We have developed a micellar electrokinetic chromatography (MEKC) method using bile salts for the simultaneous determination of six corticosteroids, including betamethasone, cortisone, prednisolone, 6alpha-methylprednisolone, triamcinolone, and prednisone. The separation was performed using borate buffer containing sodium cholate and sodium deoxycholate. Several parameters were studied, including bile salt concentrations, concentrations and pH of borate buffer, and analytical voltages. In method validation, calibration curves were linear over a range of 10-100 microM for each corticosteroid. The RSD (relative standard deviation) and RE (relative error) were all less than 5% for intra- and interday assays. The limit of detection of each analyte was 5 microM. The recoveries were greater than 95%. Application of this method for quality control of commercial tablets also proved to be feasible. All analytical values fall within the labeled amount of 90-110% for betamethasone and prednisolone, and of the labeled amount of 92.5-107.5% for 6alpha-methylprednisolone, as required by the United State Pharmacopeia 25 (USP 25).
Kuo
Chien-Yuan
CY
Graduate Institute of Pharmaceutical Sciences, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Wu
Shou-Mei
SM
D000305:Adrenal Cortex Hormones / Q000032:analysis* / Q000737:chemistry; D001623:Betamethasone / Q000032:analysis; D001647:Bile Acids and Salts / Q000737:chemistry; D001881:Borates / Q000737:chemistry; D002021:Buffers; D002851:Chromatography, High Pressure Liquid; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D003348:Cortisone / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D008775:Methylprednisolone / Q000032:analysis; D008823:Micelles; D008956:Models, Chemical; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry; D011239:Prednisolone / Q000032:analysis; D011241:Prednisone / Q000032:analysis; D013997:Time Factors; D014221:Triamcinolone / Q000032:analysis; D014466:Ultraviolet Rays
D000305:Adrenal Cortex Hormones; D001647:Bile Acids and Salts; D001881:Borates; D002021:Buffers; D008823:Micelles; D004364:Pharmaceutical Preparations; D014221:Triamcinolone; D001623:Betamethasone; D011239:Prednisolone; D003348:Cortisone; D011241:Prednisone; D008775:Methylprednisolone