title: Comparison between two methods for the determination of the total and free (R)- and (S)-disopyramide in plasma using an alpha 1-acid glycoprotein column.
abstract: Two different high-performance liquid chromatographic systems for the determination of the total and free (R)- and (S)-disopyramide (DP) in plasma and urine were compared. In method I a Nucleosil C8 column was coupled in series with an alpha 1-acid glycoprotein column. Method II consisted of two systems; a LiChrosorb Si 60 column was used for the determination of the racemic drug concentration and the R/S ratio was determined on an alpha 1-acid glycoprotein column. The recovery of (R)- and (S)-DP from plasma was greater than 97% in both methods. The precisions of the (R)- and (S)-DP determinations in plasma are high with both methods. The relative standard deviations for the determination of the free concentration do not exceed 6.5% at 1.59 micrograms/ml racemic DP. Method II is preferred as it can also be used to determine the concentration of (R)- and (S)-monodesisopropyramide. It is also easier to avoid disturbances from endogenous compounds in plasma samples with method II than with method I. It was observed that DP was incorporated into urine sediment during storage. A simple ultrasonic treatment of the urine samples was demonstrated to release DP from the sediment.
authors.affiliation: Apoteksbolaget AB, Central Laboratory, Department of Biomedicine, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Enquist
authors.forename: J
authors.initials: J
authors.lastname: Hermansson
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004206:Disopyramide / Q000097:blood* / Q000652:urine; D006801:Humans; D009961:Orosomucoid; D013237:Stereoisomerism; D014462:Ultrafiltration
chemical_list: D009961:Orosomucoid; D004206:Disopyramide