I don't know where to start, so your original assertion is probably the best bet.
Something I intend to set for straight around here, the fact sniffing #3 works for sure. People say it won't as it needs citric acid to be IV'd, however your nose has some kind of acid which breaks it downs just as effectively to be sniffed.
Right, your assertion is that intranasal administration of #3 Heroin (Freebase + Caffeine as a eutectic mixture) is effective, your reasoning being that "some kind of acid" is present and converts the freebase to a salt "just as effectively" as Citric/Ascorbate.
Which acid in particular is responsible for this conversion?
The typical environmental pH of the human nasal cavity is 6 - 6.4, average: 6.3.
Source.
The slight acidity is a result of CO2 being expelled from the lungs out of the oral and nasal cavities, somatic cell respiration, respiration of commensal aerobic microbes and the secretion of H+ from nasal epithelium cells. Carbonic Acid is present before dissociating into H+ and HCO3- ions. Various other acids are present in the mucus and surrounding tissue after being excreted as waste products by the bacterial colonies that cover large amounts of the entire respiratory tract, with S.
aureus alone colonising the nose of
~30% of the population. The enzymes present in the respiratory tract can also produce H+, most prominently lysozome.
Without energy being put into the reaction in the form of heat, protonation will occur incredibly slowly. At ~24C the nose is far cooler than the ~90C+ that direct heating of (Ascorbate/Diamorphine)[aq] causes in just a few seconds. The lack of potential energy renders the probability of Base--->Salt being relatively poor, in accordance with
Collision Theory. Thus the freebase Diamorphine is likely to remain as such. The sparse kinetic energy also increases the likelihood of just a few successful reactions; even if the salt is formed, the freebase is likely to be present in greater frequency.
Hopefully that adequately covers why snorting Heroin Base and relying on the native ions is nowhere near "just as effective" as a Citrate conversion.
And the above scenario is before solubility is even mentioned...
The simplest reason for the reduced efficacy of the Freebase compared to Diamorphine.HCl (#4) is one of the most basic concepts in Chemistry - Polar compounds will dissociate into their respective ions when dissolved in a Polar solvent, Non-polar compounds will remain bonded/will not dissolve in Polar solvents.
The mucus layer that coats the nose tissue is polar, allowing the #4 to dissolve whilst the Freebase will be caked where it falls after being snorted.
Things don't necessarily need to be water soluble to be absorbed through mucas membranes... It just makes things easier and less complex if they are.
As you seem to have found out though diacetalmorphine base is bioactive when snorted but it's bioavailable is relatively low in comparison to other ROAs
As was pointed out to you above by Englandgz, any snorted compound must be able to move across the separatory membranes - specialised cells that block uncontrolled diffusion and establish concentration gradients as a result. The nasal membranes are highly permeable to polar molecules which can diffuse across unobstructed.
The Freebase cannot move via the same mechanism, though it is highly lipophillic in this state allowing it to move freely through the lipid layer of the surrounding cells and tissues via
transmembrane transport. At this particular point both Base and Salt can move freely, but as noted above - only the #4 can cross the mucus lining without issue. The base will absorb when it, by chance and movement by air flow and current, comes into contact with lipids. The base molecules that don't reach a permeable point tend to remain in position until they are flushed out or decompose in the moist, acidic environment.
Once they enter the blood there is absolutely no difference, it's the journey they take that differs - not much of the ionic salt is lost as it breezes through the phospholipid bilayers and is highly soluble in the aqueous portions of our anatomy. The base however has difficulty with its passage, is slower to reach its target (thought not to a subjectively perceptible degree) and a significant portion may not reach circulation.
It is this distinction referred to by the term "less efficient".
Seems most people you speak to in the UK are still of the opinion the heroin we get here is not made to be sniffed.
Because it is produced specifically to be used via vapourisation as I explained here:
I should have clarified: I have used #3/Freebase Heroin intranasally on numerous occasions - it 100% works and the notion of it not being absorbed is incorrect. However, when it is described as an inefficient ROA it is in comparison to the Salt/#4 that the U.S. east coast receives as standard.
You can snort the freebase and you will get high from a sufficient dose. #3 is 99.9% of the time a combination of Diamorphine Base and Caffeine at the point of manufacture (once it's cut it's anyone's guess what else is in it), the latter is added specifically because the mixture has a much greater difference between the vaporisation point and the combustion temperature which makes it much easier to 'chase' than pure freebase which is destroyed by excess heat due to the similarity of the VP and M/CP. That is why #3 is described as 'made for smoking'.
The caffeine constituent is simply an inconvenience if using IN (unintended filler/cut), irritating the nasal passageways and reducing the surface area exposed to the Diamorphine.
#3 is by definition an impure mixture, which is a hindrance when using via IN as it competes for physical space in the cavity, it is markedly more irritating to soft tissue (inflammation reduces transport rate: slowing the H's passage), alters the necessary conc. gradients and surrounding polarity and preventing the H from reaching its target receptor.
The latter can be considered through simple math:
#3 = 8X = 4X Caffeine + 4X Heroin.
No. of target receptors = 4Y.
8X/4Y = Only half the amount of H is in transit at any point.
The subjective difference in effects between IN and Vapourisation actually has very little to do with absorption though.
They will always feel completely different regardless of their being salt or base.
It actually comes down to the route blood travels while circulating the body - gaseous Heroin diffuses across the alveolar membranes in the lungs almost instantly, absorbing through capillary walls and heading directly to the brain with the oxygenated blood from the lungs. That is why vaping gives almost immediate effects but wears off rapidly.
If Freebase is inhaled the effect is amplified as the lipophilicity allows rapid permeation of the BBB.
The relationship is akin to Cocaine Freebase and HCl - one is formulated specifically to be inhaled.
Snorting Crack and smoking HCl would both provide effects but be
inefficient in the same way snorting Heroin Freebase is.
Even dealers are selling #3 as "sniff, smoke or IV it with citric". They also sniff the pure tar over in the states (the drier stuff) and it works.
Dealers say a lot of incorrect shit, they've got a slight vested interest...
Tar is not the same as UK #3, it actually couldn't be much less similar so that notion is irrelevant.
The natural acids in the nose will form Diamorphine salts, yes, but their overall effectiveness is massively reduced outside sterile laboratory conditions - the average person's nasal tissue is a smorgasbord of airborne particulates, dead lymphocytes, viral particles, mucus, pollen, aerosols and an almost infinite number of objects that all alter the pH balance and chemical environment of the nose cavity. Thus it is much more sensible to form a stable ionic salt of Diamorphine which will absorb and diffuse reliably, rapidly and efficiently across the membrane than to use a form which is diluted and requires chemoconversion which can be halted by a localised infection like the common cold.
You seem to be posting this like it's fact Sprout. For instance saying about what the average persons nose is full of, and making out it means that the pH of the mucus membranes breaking down #3 is not possible to be effective, when the fact is you don't know that, just like I can't prove they are breaking it all down effectively, and there seems to be little in the way of scientific proof on the matter online either way I find.
All I posted was a logical evaluation of the debate ongoing with information that is easily corroborated.
There is endless academic literature that could be cited if you understand the basic science behind it, like this
list of mucus contents or the various sources at the top of this post.
This quote: "During an infection, inflammation makes the pH of the mucus similar to that of plasma, 7.4" from
Section 2.4 of here
If you get the urge to swing by and boldly claim everyone else, not to mention independent scientific data, is completely wrong it would help if have a more convincing argument than your own singular anecdote.
"The fact is
don't know"?
Weasel words baking in glorious irony.