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Organoleptic Assessment and Median Lethal Dose Determination of Oral Carfentanil in Rats

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Technical Report,01 Mar 2019,31 May 2019

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US Army Medical Research Institute of Chemical Defense Aberdeen Proving Ground United States

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Carfentanil is an incredibly potent and toxic fentanyl analogue that has been targeted as a public health concern. Due to its availability and chemical properties, carfentanil is a potential ingestion hazard, as very small amounts can adulterate a large amount of food or drink. We developed a rat model of voluntary oral ingestion to determine the potential risk carfentanil poses. First, the solubility of carfentanil was assessed in popular consumer beverages bottled water, apple juice, and 2 milk. Lethality was then assessed by administering carfentanil in bottled water via gavage. A probit model was fit to 24-hour survival data and predicted a median lethal dose of 1.65 mgkg 95 CI 0.46 2.96 mgkg slope 3.23. Finally, the organoleptic properties i.e., taste, smell, texture, etc. were assessed by allowing rats to voluntarily consume 3.0 mL of beverages adulterated at various concentrations. The organoleptics assessment determined that carfentanil was readily detected in water, but was consumed in significantly higher amounts in juice and milk, suggesting these beverages masked its taste or some other sensory property. Buccal absorption also proved to be important, as lethality in the organoleptics assessment was higher than predicted from the lethality assessment utilizing oral gavage. Because rats have more developed chemoreceptive capabilities than humans and are more resistant to opioids, these results suggest that carfentanil may be unwittingly consumed in toxic or even lethal concentrations by humans in a variety of beverages.

Subject Categories:

  • Medicine and Medical Research

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