tailieunhanh - Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 33)

Introduction: Diphenylmethane antihistaminics are being widely used for treatments of allergy, motion (travel) sickness and cold. They are also being sold as over-the-counter drugs. The structures of principal drugs of this group are shown in Figure . They are being analyzed by GC [1–6] and HPLC [7–13]. In this chapter, a GC method for simultaneous analysis of diphenylmethane antihistaminics and also HPLC methods for some representative drugs of this group are presented. | Diphenylmethane antihistaminics by Yoko Hieda and Kojiro Kimura Introduction Diphenylmethane antihistaminics are being widely used for treatments of allergy motion travel sickness and cold. They are also being sold as over-the-counter drugs. The structures of principal drugs of this group are shown in Figure . They are being analyzed by GC 1-6 and HPLC 7-13 . In this chapter a GC method for simultaneous analysis of diphenylmethane antihistaminics and also HPLC methods for some representative drugs of this group are presented. Simultaneous analysis by GC 4 Reagents and their preparation Diphenhydramine hydrochloride diphenylpyraline hydrochloride phenyltoloxamine citrate orphenadrine hydrochloride benactyzine hydrochloride doxylamine succinate carbinoxamine maleate chlorpheniramine maleate triprolidine hydrochloride homo-chlorcyclizine dihydrochloride hydroxyzine dihydrochloride clemastine fumarate and meclizine dihydrochloride can be purchased from Sigma St. Louis MO USA . Pure p owder of terodiline hydrochloride and piperilate hydrochloride was donated by Kissei Pharmaceutical Co. Ltd. Nagano Japan and Nippon Shinyaku Co. Ltd. Kyoto Japan respectively. Sep-Pak C18 cartridges classic type were purchased from Waters Milford MA USA . Other common chemicals were of the highest purity commercially available. Care should be taken for that all of the above 15 kinds of drugs are in the salt forms. All compounds 5-mg each as the weight of its free base are altogether dissolved in methanol to prepare 10 mL solution a 10-pL volume of the mixture solution is spiked into 1 mL of whole blood or urine. One of the 15 drugs is selected for use as internal standard IS . Chloroform methanol 9 1 and distilled water 100-200 mL each are prepared. M NaHCO3 solution a aliquot of NaHCO3 is dissolved in distilled water to prepare 100 mL solution. GC conditions GC column DB-1 15 m x mm i. d. film thickness pm DB-17 15 m x mm i. d. film thickness pm .