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how long does it take for heroin to hydrolyze into morphine?

molotovsix

molotovsix

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Jul 7, 2006
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I've been wondering... approx. how long would it take for diacetylmorphine to hydrolyze back to morphine & acetic acid in water?

I am so sorry for asking this again, but I asked this in 'other drugs' and nobody had any conclusive thoughts on this. I want to know how long it takes for heroin to become morphine in water, say, in a syringe. I have heard anything from a few minutes to 24 hours to a few days, and everything in between, but nothing concrete. If anybody could help me, I would be so very grateful.
 
My impression is that this kind of esterification-deesterification is an equilibrium reaction, so the rate of reaction and equilibrium shift is dependent upon entropic and enthalpic factors. So the short answer is I'm not sure, and if I had already taken physical chemistry I could probably give you some terrible partial differential equation to describe it.
 
Because of the fast hydrolysis heroin is more potent than morphine only when administered i.v. or by smoking. Taken i.m. or by snorting it is indistiguishable from morphine (at least I have not found any difference, and I do not like either drug). In vivo the half-time of the hydrolysis of the phenol acetyl group is ~ 2 min. The other acetyl is a bit more stable, but it hydrolyses too. BTW monoacetylmorphine is stronger than morphine.
 
Spontaneous hydrolysis of heroin in buffered solution.

Smith PT, Hirst M, Gowdey CW.

Electron-capture gas-liquid chromatography was used to study the spontaneous hydrolysis of heroin in phosphate buffer (pH 6.4 and pH 7.4) at 23 degrees C. Aliquots of solution were taken over a 24-h period. After extraction at pH 8.9 into propan-2-ol (10%)-ethyl acetate, deacetylated products were made into hepafluorobutyrate derivatives which were analyzed quantitatively using nalorphine as the internal standard. Heroin decomposes to 06-monoacetylmorphine (06-MAM) under these conditions. Further decomposition to morphine was not observed. Spontaneous hydrolysis was faster at pH 7.4 (first-order rate constant, 9.6 x 10-5 min-1) than at pH 6.4 (first-order rate constant, 3.0 x 10-5 min-1). In 24 h, the decomposition to 06-MAM was 13 and 4%, respectively.

PMID: 688091 [PubMed - indexed for MEDLINE]



that answers the question but its not easy to figure out

from what i understand it depends on quite a few variables
 
^ agreed. I think the last sentence should mean something:

" In 24 h, the decomposition to 06-MAM was 13 and 4%, respectively."

Looks like the hydrolysis is pretty damn slow (but as johnnyb420 said, thats under THOSE variables, so who knows)
 
I think some pretty valid conclusions can be reached from this. They took heroin and stuck it in two pH buffered solutions, let it sit for 24 hours at room temp, and then measured how much degraded. Just because they did it in a phosphate buffer solution doesn't mean we can't extrapolate with relatively good accuracy to a shot sitting in saline or distilled water. I think from this data we can say roughly that you can expect to lose about 8% to 10% of your heroin if you let it sit overnight in a neutral aqueous solution at room temp. If you heat it up expect more to degrade, if you chill it expect less.
 
sorry for bumping a dead thread but this has been on my mind for a while today. im wondering specifically how long it would take pharmaceutical grade and black tar heroin to convert back into morphine in water respectively. can anyone shed some light in layman's terms out on this subject?
 
At room temperature and neutral pH the 1/2 life of simple esters is measured in years. Heroin may be a little more reactive, since it is an aromatic ester, so I'm guessing that it may be around a year. If you add acid or base and heat it, the hydrolysis takes only hours.
 
methylenedioxy said:
BTW monoacetylmorphine is stronger than morphine.
Click to expand...
and
pubmed said:
Heroin decomposes to 06-monoacetylmorphine (06-MAM) under these conditions. Further decomposition to morphine was not observed.
Click to expand...

Also, since water isn't a buffered solution, results may depend on whatever the dope is cut with. Drop it on red litmus and see what happens.
 
Add a little bit of acetic acid to the solution to drive the reaction equilibrium to the left and voila... no hydrolysis.
 
wungchow said:
Add a little bit of acetic acid to the solution to drive the reaction equilibrium to the left and voila... no hydrolysis.
Click to expand...

Nope, a little bit is not enough to compete with the 55 M water. You need to decrease the water activity to change the equilibrium significantly.
 
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