Acute Biodistribution Comparison of Fentanyl and Morphine
, D. Matthew Walentiny, William Dewey and Matthew Halquist *Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThank you for the opportunity to review this manuscript. All my comments are in the attachment. I want to point out some things, the abstract is too long. The whole manuscript is too long. I understand that the authors worked a lot, but I suggest them to rewrite the article and include just the relevant data because the manuscript is very difficult to read.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe work presented describes the quantified biodistribution of morphine and fentanyl in mice. Most interestingly, the concentrations used produce respiratory depression. The work is likely to be of interest to those working to address the current opioid epidemic. Prior to publication, the follwoing points should be addressed:
1. The chemical structure for morphine is incorrect and needs to be corrected. Morphine does not contain a seven member ring but rather a six membered ring.
2. Why is the structure of fentanyl protonated and morphine is not? The protonation state for both should be consistent since they contain the same functional group with the same pKa.
3. It is not clear why Tables 2, 3, and 5 do not have error calculations. It would seem more appropriate to provide some insight into the range of values observed.
4. It is this reviewer's opinion that the discussion is overly long compared to the experiments conducted. While the attempt to contextualize the results seen with other literature is valued, the authors are excessive. It is recommended that the discussion section be appropriately shortened.
Comments on the Quality of English LanguageFine.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI understand that all the tissues from all groups were stored in the same manner but directly stored at -80 degrees without first immersing in liquid nitrogen can affect the assay.
