title: Simultaneous determination of ingredients in a cold medicine by cyclodextrin-modified microemulsion electrokinetic chromatography.
abstract: Cyclodextrin-modified microemulsion electrokinetic chromatography (CD-MEEKC) was used to simultaneously determine 14 active ingredients (thiamine nitrate, anhydrous caffeine, acetaminophen, riboflavin, guaifenesin, pseudoephedrine hydrochloride, ascorbic acid, ethenzamide, DL-methylephedrine hydrochloride, dihydrocodeine phosphate, ibuprofen, noscapine, carbinoxamine maleate, and bromhexine hydrochloride) in a cold medicine. Separation of the ingredients was optimized by changing the SDS concentration and oil type and the addition of 2-propanol and cyclodextrin (CD) to the separation solution. The separation selectivity was improved dramatically by changing CD type. All of the active ingredients and formulation excipients were successfully separated with the use of a separation solution consisting of 0.81% (w/w) pentane, 6.61% (w/w) 1-butanol, 2% (w/w) 2-propanol, 4.47% (w/w) SDS, and 86.11% (w/w) 10 mM sodium tetraborate solution with 3 mM 2,6-di-O-methyl-beta-CD. The established method was then validated and demonstrated to be applicable to the determination of the active ingredients in a model cold medicine. No interference from the formulation excipients was observed. Good linearities were obtained with correlation coefficients above 0.999. Recovery and precision ranged from 99.1 to 100.7% and from 0.5 to 2.8% R.S.D., respectively. The detection limit for ingredients ranged from 0.6 to 4.2 microg ml(-1). Good agreement was obtained between the established method and the traditional HPLC method. These results suggest that CD-MEEKC can be used for the determination of multiple ingredients in cold medicine.
authors.affiliation: Analytical Laboratory, Taisho Pharmaceutical Co. Ltd., Saitama 331-9530, Japan. h.okamoto@po.rd.taisho.co.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamoto
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakajima
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ito
authors.forename: Takao
authors.initials: T
authors.lastname: Aketo
authors.forename: Kenji
authors.initials: K
authors.lastname: Shimada
authors.forename: Susumu
authors.initials: S
authors.lastname: Yamato
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D003139:Common Cold / Q000188:drug therapy*; D003505:Cyclodextrins / Q000032:analysis*; D004563:Electrochemistry; D004655:Emulsions; D004366:Nonprescription Drugs / Q000032:analysis* / Q000737:chemistry / Q000627:therapeutic use; D015203:Reproducibility of Results
chemical_list: D003505:Cyclodextrins; D004655:Emulsions; D004366:Nonprescription Drugs