Cocaine: plasma concentrations after intranasal application in man.

@article{Dyke1976CocainePC,
  title={Cocaine: plasma concentrations after intranasal application in man.},
  author={Craig van Dyke and Paul G. Barash and Peter I. Jatlow and Robert Byck},
  journal={Science},
  year={1976},
  volume={191 4229},
  pages={859-61}
}
Cocaine (1.5 milligrams per kilogram) was applied to the nasal mucosa of human subjects. The cocaine persisted in the plasma for 4 to 6 hours and reached peak concentrations of 120 to 474 nanograms per milliliter at 15 to 60 minutes. In that residual cocaine was detectable on the nasal mucosa for 3 hours, continuous absorption secondary to its vasoconstrictive action might explain its persistence in the plasma.