Talk:Bioavailability

message: Can we have a discussion about bioavailability in the context of ecology?  For instance, what it means for a particular molecule to be bioavailable to a microbe.  I think this is an important definition of bioavailability, though, I'm not the one to define it.  Any takers? --Jen Duane 08:28, 15 November 2005 (UTC)
thread_title: Ecological Bioavailability

message: I think  this article should be split into
# Bioavailability from a biological/ecological viewpoint 
# Bioavailability from an environmental viewpoint 
# Bioavailability from the point of view of human health and nutrition
"Bioavailability has been defined differently by various disciplines, which has confounded use of the term. For this reason, the NRC (-I assume US National Research Council-) report contains no explicit definition of bioavailability" 
Ehlers, L. J.; Luthy, R. G. Contaminant bioavailability in  soil and sediment. Environ. Sci. Technol. 2003, 37, 295A–302A.
The same article defines bioavailability in this way: 
"Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants [in the environment]"
Another article sees bioavailability as "[...] a descriptor for the rate and extent of biodegradation [...]" and gives example of definition that have been proposed earlier for the field of environmental pollution.
Semple, K.T.; Doick, K.J.; Wick, L.Y.; Harms, H. Microbial interactions with organic contaminants in soil: Definitions, processes and measurement. Env. Pol. 2003, 150, 166-176.
Riennn (talk) 13:44, 28 September 2009 (UTC)
thread_title: Environmental Bioavailability

message: In the formula for Absolute Availability: F = \frac{[AUC]_{po}*dose_{IV}}{[AUC]_{IV}*dose_{po}}, what does the 'po' mean? I guess it is related to 'extra-vascular', but it is not obvious.
What does the 'dose-corrected AUC' mean? — Preceding unsigned comment added by Duncan.france (talk • contribs) 22:45, 18 March 2006 (UTC)
replies: text: Hi Duncan.france, "po" is conventional medical abbreviation for per os (by mouth). It made more sense when I originally wrote this article, because (to keep things simple) I only referred to absolute bioavailability of orally-administered drugs. But since people have added comments about other extravascular routes, I've now modified the text to try to explain. Dose corrected AUC means that doses of the drug given IV or non-IV can be different, so the formula for calculating F takes this into account. Hope that helps – let me know if it needs to be clarified further in the text. -Techelf 09:14, 20 March 2006 (UTC)

text: The page you cite actually just contains another way of expressing the same formula (think about it)... -Techelf 10:56, 4 April 2006 (UTC)
thread_title:  Explanation please... 

message: I noticed multiple grammatical errors while reading this article. I would correct them but I'm on an iPhone and quite limited at this moment. To find an example, text search for "such that". Don't remember the context exactly.
Sporky023 (talk) 23:24, 18 November 2010 (UTC)
thread_title:  Grammatical errors 

message: In the article bioavailability has been called both 'rate' and 'extent'. By definition and use, bioavailabilty is a fraction and thus a dimensionless quantity. Thus, it cannot be a 'rate'.Ashu 18:08, 21 January 2012 (UTC)
replies: text: Hi Ashu! You are right; pharmacologists mean by bioavailability the ratio of AUCs (dimensionless f or if given as a percentage denoted by F). Rate of bioavailability is only given in connection with bioequivalence testing following FDA's (and all regulatory agencies worldwide) terminology. See CFR Title 21, Volume 5, Part 320.23 (a)(1): The in vivo bioavailability of a drug product is measured if the product's rate and extent of absorption, as determined by comparison of measured parameters, e.g., concentration of the active drug ingredient in the blood, urinary excretion rates, or pharmacological effects, do not indicate a significant difference from the reference material's rate and extent of absorption. This definition is clumsy but we have to live with it (legally binding). Depending on the formulation (given in product-specific guidances) generally the ratio of Cmax-values or the ratio of partial AUCs (AUC from the time point of administration to the time point of the median tmax of the population under the reference treatment) has to be assessed. This ratio is also dimensionless. Alfie↑↓© 14:04, 23 January 2012 (UTC)
thread_title:  Clarification 

message: Bioavailability is an important concept in nutrition.  "Mineral X in ... food, but it is not bioavailable because ".  That kind of discussion.  One idea is to have two articles, Bioavailability(pharmaceuticals) and  Bioavailability(nutrition).  --Smokefoot (talk) 20:11, 25 August 2023 (UTC)
thread_title: Broaden the article?