Topical cocaine is used as local anesthesia of the upper airway mucous membranes. This study’s objective was to define the safety and efficacy of topical intranasal cocaine for a subsequent phase II clinical trial.

This study was a single-dose, single-center, and open-label study of the plasma and urinary PK of four percent topical cocaine and its primary metabolites, BE and EME, in thirty healthy subjects.

Researchers enrolled a total of 30 subjects, treated, and provided PK data for analysis. Mean plasma concentrations then quickly fell and monoexponentially for the remainder of the study, with a mean half-life of 1.04 ± 0.35 hours. Following a 20-minute topical intranasal exposure to a 160 mg dose of cocaine 4% solution, the mean 0 to 12 hours recoveries of cocaine, BE, and EME were 117 ± 67 μg, 816 ± 440 μg, and 275 ± 113 μg, respectively. Plotting urinary recovery by collection interval showed that urinary excretion of cocaine closely followed the time course of plasma cocaine.

The study concluded that cocaine was rapidly but incompletely absorbed and then rapidly eliminated. Only 4% of the administered cocaine dose appeared to be immersed in this study. Cocaine appeared in the urine with a time course similar to that in plasma.