Trace level determination of doxylamine in nonhuman primate plasma and urine by GC/NPD and HPLC.

Bendectin contains doxylamine succinate and is used for the treatment of nausea and vomiting in pregnant women. Trace level analytical chemical procedures for analysis of doxylamine in primate urine and plasma were required before toxicological tests with the drug in three species of nonhuman primates could be performed. A gas chromatographic procedure using a nitrogen phosphorus detector was developed to quantitate doxylamine in primate plasma at levels as low as 100 ppb. A high-pressure liquid chromatographic procedure was also developed to assay the drug in primate urine at levels as low as 250 ppb. Data from stability studies with the drug in plasma at -5 degrees and -20 degrees C, and recovery of the drug from Bendectin tablets, plasma, and urine are also presented.