Simultaneous Determination of Cloperastine，Chlorpheniramine and Psedoephedrine Concentrations in Human Plasma by LC-MS

OBJECTIVE To establish an LC-MS for simultaneous determine the concentration of cloperastine，chlorpheniramine and psedoephedrine in human plasma and to apply this method to the pharmacokinetic and bioavailability study of above components after oral administration of a compound preparation. METHODS Using diphenhydramin hydrochloric as internal standard, plasma was extracted with ethyl acetate and separated by a C18 column with the mobile phase of methanol-water (including 0.5‰ acetic acid and 0.5 mmol·L-1 ammoniium acetate). LC-MS was performed in the selectedion monitoring mode using target ions was at m/z330.1 for cloperastine，m/z 275.0 for chlorpheniramine,m/z 166.0 for psedoephedrine and m/z 256.15 for diphenhydramin hydrochloric(IS).The fragmentor voltage was 25 V. RESULTS The linear range of cloperastine,chlorpheniramine and psedoephedrine in human plasma were 0.5-50.0,0.2-25.0 and 6.25-400.0 ng·mL-1, respectively.The limit of determination were 0.5, 6.25 and 0.2 ng·mL-1, respectively.The recoveries of methodology were all more than 85%. The inter-day and intra-day RSD were all less then 10%. CONCLUSION This method has good sensitivity and precision.It is shown to be suitable for pharmacokinetics studies of different compound preparations containing low dosage of cloperastine,chlorpheniramine,psedoephedrine.