@article {41148,
	title = {Urinary excretion of chlorpheniramine and pseudoephedrine in humans.},
	journal = {J Pharm Sci},
	volume = {68},
	year = {1979},
	month = {1979 Oct},
	pages = {1243-6},
	abstract = {A specific high-pressure liquid chromatographic method for the determination of chlorpheniramine and pseudoephedrine in urine was developed and applied in a urinary excretion study of normal healthy subjects who received a sustained-release dosage form contianing 8 mgof chlorpheniramine maleate and 120 mg of pseudoephedrine hydrochloride. Five subjects received one dose on Day 1, followed by multiple dosing every 12 hr for 7 days without ammonium chloride administration. Four subjects received one dose of the sustained-release dosage form together with ammonium chloride. Urine samples were collected during the 1st day and at steady state. The method is specific and simultaneously determines choorpheniramine, two metabolites (mono- and di-desmethylchlorpheniramine), pseudoephedrine, and norpseudoephedrine. The assay recovery was less than 97\% (0.06-3 microgram/ml) for chlorpheniramine maleate and less than 98\% (1.5-75 microgram/ml) for pseudoephedrine hydrochloride. Excretion of chlorpheniramine and its two metabolites in urine was enhanced after ammonium chloride administration. At steady state, a change in urine pH from 5.69 to 6.46 resulted in more than a 25\% decrease in chlorpheniramine and monodesmethylchlorpheniramine excretion. In spite of expected changes in its biological half-life, the overall amount of unchanged pseudoephedrine excreted in urine was not affected by urine pH, presumably because it is primarily excreted in urine as intact drug.},
	keywords = {Chlorpheniramine, Delayed-Action Preparations, Drug Combinations, Ephedrine, Humans, Hydrogen-Ion Concentration, Male, Time Factors},
	issn = {0022-3549},
	doi = {10.1002/jps.2600681012},
	author = {Lai, C M and Stoll, R G and Look, Z M and Yacobi, A}
}
