Collaborative Method Performance Study of the Measurement of Nicotine, Its Metabolites, and Total Nicotine Equivalents in Human Urine.

Biomarkers of tobacco exposure have a central role in studies of tobacco use and nicotine intake. The most significant exposure markers are nicotine itself and its metabolites in urine. Therefore, it is important to evaluate the performance of laboratories conducting these biomarker measurements.

Interlaboratory comparability of serum cotinine measurements at smoker and nonsmoker concentration levels: a round-robin study.

Introduction: Cotinine, the primary proximate metabolite of nicotine, is commonly measured as an index of exposure to tobacco in both active users of tobacco and nonsmokers with possible exposure to secondhand smoke (SHS). A number of laboratories have implemented analyses for measuring serum cotinine in recent years, but there have been few interlaboratory comparisons of the results. Among nonsmokers exposed to SHS, the concentration of cotinine in blood can be quite low, and extensive variability in these measurements has been reported in the past.

Relative bioavailability and pharmacokinetics of two oral formulations of docosahexaenoic acid/eicosapentaenoic acid after multiple-dose administration in healthy volunteers.

Objectives: To assess the comparative pharmacokinetic profile and bioavailability of docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) after multiple-dose administration of a new oral formulation (test formulation) and a commercially available reference formulation in healthy subjects.

Methods: Forty-eight healthy subjects received a 28-day oral treatment with DHA/EPA in the form of either the test or the reference product according to an open-label, randomized, parallel-group design. Both formulations were given t.