Determination of ephedrine, theophylline and phenobarbital in a tablet dosage form by capillary electrophoresis.
A capillary electrophoresis method was developed to separate and quantitate ephedrine (ED), theophylline (TP) and phenobarbital (PB) in a tablet dosage form. Tablets were ground and extracted with methanol using ultrasonication. Aliquots of standard stock solution were hydrodynamically injected for 5 s at the anodic end. Separation was performed on a fused silica capillary (72 cm x 50 microm i.d.; 50 cm to detector) at an applied voltage of 20 kV with a phosphate run buffer (pH 8.0, 50 mM). Analysis was performed at ambient temperature (23+/-1 degrees C) and the total run time was 9 min with detection at 220 nm. Calibration curves were prepared for ED, TP and PB with methyl p-hydroxy benzoate as internal standard. For each analyte, the correlation coefficients were >0.999 (n = 4). The RSD% of ten replicate injections for each analyte were <1%. The method was applied to the quantitation of ED, TP and PB in a commercial tablet dosage form.
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Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens 30602-2352, USA.
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Stewart
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D002138:Calibration; D004338:Drug Combinations; D019075:Electrophoresis, Capillary / Q000379:methods; D004809:Ephedrine / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D010226:Parabens / Q000032:analysis; D010634:Phenobarbital / Q000032:analysis*; D012680:Sensitivity and Specificity; D013607:Tablets / Q000032:analysis / Q000737:chemistry; D013806:Theophylline / Q000032:analysis*
D004338:Drug Combinations; D010226:Parabens; D013607:Tablets; C015358:methylparaben; D013806:Theophylline; D004809:Ephedrine; D010634:Phenobarbital