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Methods and efficiency of different ways to ingest THC

Goanaut

Bluelighter
Joined
Oct 9, 2002
Messages
145
this may be pretty much basic....

can anyone post the well know statistics for methods of smoking and their respective THC absorption levels...

My real question is....what about holding your smoke in? I have come into the practice of taking a large hit, exhaling until I see smoke, inhaling again, exhale again until I see smoke, then repeat so as to both increase the flow of gases around my lungs and to increase the time available for absorption. What about holding a hit in for a longer period of time? I also have veteran smoker friends who simply inhale and exhale without holding it in and claim that they do not miss out on any of the active chemicals in the smoke.

can anyone post a definitive synopsis?
 
Well my psychopharm textbook is in a different state than me right now but if I remember correctly eating THC allows about 5-6% to be absorbed by the body and used. Smoking allows up to 16-19% available to be absorbed, but a habitual and experienced smoker can get as much as 23% available. So smoking is probably the most efficient way to go.
 
Pharmacokinetics and Pharmacodynamics of Cannabinoids
Franjo Grotenhermen
Clin Pharmacokinet 2003; 42 (4): 327-360
3.1.1 Inhalation
THC is detectable in plasma only seconds after the first puff of a cannabis cigarette[35] with peak plasma concentrations being measured 3–10 minutes after onset of smoking (figure 5).[35-40] Systemic bioavailability generally ranges between about 10 and 35%, and regular users are more efficient (table III).[38] Bioavailability varies according to depth of inhalation, puff duration and breathhold. A systemic bioavailability of 23 ± 16%[38] and 27 ± 10%[42] for heavy users versus 10 ± 7% and 14 ± 1% for occasional users of the drug was reported. In a study with a smoking machine, patterns of cannabis smoking were simulated with regard to puff duration and volume,[43] resulting in 16 to 19% of THC in the mainstream smoke. If the whole cigarette was smoked in one puff the percentage of THC in the mainstream increased to 69%. About 30% is assumed to be destroyed by pyrolysis. With smoking, additional THC is lost in the butt, in sidestream smoke, and by incomplete absorption in the lungs. Smoking a pipe that produces little sidestream smoke may also result in high effectiveness, with 45% of THC transferred via the mainstream smoke in one smoker tested.[23]

3.1.2 Oral Administration
With oral use, absorption is slow and erratic, resulting in maximal plasma concentrations usually after 60–120 minutes (figure 6).[31,39,44] In several studies, maximal plasma concentrations were observed as late as 4 hours[45] and even 6 hours in some cases.[39,41,46] Several subjects showed more than one plasma peak.[37,39,41] Delta-9-THC is expected to be degraded by the acid of the stomach and in the gut.[18] At low pH, isomerisation to ?8-THC and protonation of the oxygen in the pyran ring may occur with cleavage to substituted CBDs.[18] It has been suggested that a somewhat higher bioavailability is obtained in an oil formulation.[47] However, absorption seems to be nearly complete in different vehicles. Ninetyfive percent of total radioactivity of radiolabelled THC was absorbed from the gastrointestinal tract in an oil vehicle[31] and 90–95% if taken in a cherry syrup vehicle,[48] but it is unclear from these data how much of this radioactivity belongs to unchanged THC and how much to breakdown products. An extensive first-pass liver metabolism further reduces the oral bioavailability of THC, i.e. much of the THC is initially metabolised in the liver before it reaches the sites of action. Ingestion of THC 20mg in a chocolate cookie[39] and administration of dronabinol 10mg[41] resulted in a very low systemic bioavailability of 6 ± 3% (range 4–12%)[39] or 7 ± 3% (range 2–14%),[41] respectively, with a high interindividual variation.

3.1.3 Ophthalmic Administration
A study in rabbits with THC in light mineral oil determined a variable systemic bioavailability of 6–40% with ophthalmic administration.[49] Plasma concentrations peaked after 1 hour and remained high for several hours.

3.1.4 Rectal Administration
With rectal application, systemic bioavailability strongly differed depending on suppository formulations. Among formulations containing several polar esters of THC in various suppository bases, THC-hemisuccinate in Witepsol H15 showed the highest bioavailability in monkeys and was calcu- lated to be 13.5%.[50] The rectal bioavailability of this formulation was calculated to be about as twice as high as oral bioavailability in a small clinical study.[25]

3.1.5 Sublingual Administration
Clinical studies are under way using a liquid cannabis extract applied under the tongue. A phase I study in six healthy volunteers receiving up to 20mg of THC was reported to result in ‘relatively fast’ effects.[27] In phase II studies, THC plasma concentrations of up to 14 µg/L were noted.[51]

3.1.6 Dermal Administration In a study using the more stable ?8-THC isomer, the permeability coefficient of THC was significantly enhanced by water and by oleic acid in propylene glycol and ethanol,[52] resulting in significant THC concentrations in the blood of rats. Studies designed to develop transdermal delivery of cannabinoids found a mean effective permeability coefficient for ?9-THC in propylene glycol of 6.3 × 10–6 cm/h.[26]

Anyone interested in cannabinoid pharmacology should get their own copy of that article.
 
Thats a fantastic article. First tidbit on Transdermal delivery I have been able to see. Does anyone here know anything about transdermal thc delivery or have tried it. I have tried it years ago but my procedure was so flawed I am embarrassed to mention it.

I used isopropyl alcohol IPM Oleic Acid and DMSO. I then soaked some low grade leaf bud in all of the solvents. The DMSO was def too strong a solvent and basically liquified all the leaf material. When I applied it to my skin (way too little to get high) I got some minor chemical burns with some nasty looking bumps... not nice.

I think if you were to use a thc oil you might have different luck.
 
I have come into the practice of taking a large hit, exhaling until I see smoke, inhaling again, exhale again until I see smoke, then repeat so as to both increase the flow of gases around my lungs and to increase the time available for absorption.

This is how I smoke too. I don't have any proof or scientific data, but I think it is much more efficient than just holding in the smoke and exhaling it all at once. This method lets you get oxygen while still holding in most of the smoke, giving your lungs more time to absorb the THC without depriving yourself of oxygen. And because you are getting some oxygen you can hold the hit in longer.
 
Thats also way longer the smoke is in your lungs and particulate is settling on your lungs. ICK but I guess if you smoke you are charing them anywys.
 
BigBenn said:
Thats a fantastic article. First tidbit on Transdermal delivery I have been able to see. Does anyone here know anything about transdermal thc delivery or have tried it. I have tried it years ago but my procedure was so flawed I am embarrassed to mention it.

I used isopropyl alcohol IPM Oleic Acid and DMSO. I then soaked some low grade leaf bud in all of the solvents. The DMSO was def too strong a solvent and basically liquified all the leaf material. When I applied it to my skin (way too little to get high) I got some minor chemical burns with some nasty looking bumps... not nice.

I think if you were to use a thc oil you might have different luck.

...im sure you're on to something (with the oil)

can i ask why you chose DMSO as a preparation method?
 
DMSO penetrates the skin extremely well, and is well known for being able to carry dissolved compounds into the bloodstream through the skin in this way.
 
when i make bud butter I have to wear gloves for the part when i sqeeze the weed & butter to strain out the last of it, because i could feel a very strange kind of high hit me. Thats funny now that I see that water and an oleic acid is the best way to get it through you skin cause thats how you make bud butter, with butter and water.
 
yeah, I've definately felt that too... though I don't know why you'd want to stop it!

Though I wonder if a lipid (i.e. butter) is either 1) as good as passing through lipid membranes as a free fatty acid (i.e. oleaic acid and 2) helps other chemicals pass through membranes as well as a free fatty acid.
 
i like it...

and i want to know if you can eat something that will increase the bioavailability of thc and 11-hydroxy-thc
 
After harvesting the males from my crop I extract the resin with acetone and then mix it with sunflower oil or other neutral oil and stores it dark and cool. When drunk or smeared on the body ('witches' and 'anointing' comes to mind, hm? :)) this induces a very pleasant lightheaded high.
 
what about IM?...why no mention of that...wondefr the absorption and feel of an oil based...may be nice prolonged but potent effect...any just curious :D
 
If the whole cigarette was smoked in one puff the percentage of THC in the mainstream increased to 69%.
I would love to see a human accomplish this--suck that motherfucker down.
 
heh heh yeahhh

but hey--lets talk oral administration and using inhibitors or carrier molecules or something that would let the oral bioavailability be raised to like 30 -100% (unlikely, but hey you guys are crazy with your chem know how)
 
Riemann Zeta said:
I would love to see a human accomplish this--suck that motherfucker down.

I had a friend who used to try this all the time. Never even got close, and coughed really freaking hard all the time.

was still hilarious to watch; and these were just cigs-cigs, not thc-cigs.
 
What you really need is one of the hyposprays, much like the ones used in Star Trek - they really exist and work by means of a very high speed/pressure jet of solution penetrating the skin with no need for needles or the like(basically an instant version of transdermal delivery systems).

Only problem is, last time I looked they were horribly expensive bits of kit!
 
i would think there is a way to aeorsolize THC and have it in a one hit inhaler so that would more than do the trick with full absorption perhaps

...or do i just sound like i might be high =D
 
fastandbulbous said:
What you really need is one of the hyposprays, much like the ones used in Star Trek - they really exist and work by means of a very high speed/pressure jet of solution penetrating the skin with no need for needles or the like(basically an instant version of transdermal delivery systems).

Only problem is, last time I looked they were horribly expensive bits of kit!

Do you have any links to more information about this?
 
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