Cold water extraction
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218549135
2008-06-11T03:40:07Z
Galaxiaad
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[[WP:UNDO|Undid]] revision 218519628 by [[Special:Contributions/71.53.85.234|71.53.85.234]] ([[User talk:71.53.85.234|talk]])
'''Cold water extraction''' (CWE) is the process whereby a substance is extracted from a mixture via cold water. It is a type of [[Fractional crystallization (chemistry)|fractional crystallization]].
The process generally involves taking a mixture of substances, dissolving them in warm water, and then cooling the mixture. The insoluble compounds [[precipitate]] out of the water, while the soluble ones stay dissolved. The solution can then be separated by [[filtration]] or [[decantation]].
This process works by exploiting the differences in [[solubility]] (with respect to temperature) of varying substances.
==Opioid extraction==
In some countries, tablets are available [[Over-the-counter drug|over the counter]] (in others these are available only by [[medical prescription]]) that contain [[aspirin]], [[paracetamol]] (acetaminophen) or [[ibuprofen]] in combination with [[codeine]], an [[opiate]]. Cold water extraction of codeine has become popular among [[recreational drug use]]rs because it speeds up absorption and reduces [[hepatotoxicity]] caused by paracetamol and [[Gastrointestinal tract|gastrointestinal irritation]] caused by aspirin and ibuprofen. However, without careful measurement of the insoluble product removed during the process, it is conceivable that one could actually cause damage to the liver by using ''many'' low dose tablets in an inefficient process. This method is also used to extract [[hydrocodone]], [[dihydrocodeine]], and [[oxycodone]] from similar (usually prescription-only) compounds.
These extractions are possible because opioid salts (codeine phosphate<ref>[http://bulkpharm.mallinckrodt.com/_attachments/msds/CODPH.htm Codeine phosphate MSDS]</ref>, hydrocodone bitartrate<ref>[http://bulkpharm.mallinckrodt.com/_attachments/msds/codon.htm Hydrocodone bitartrate MSDS]</ref>, oxycodone hydrochloride<ref>[http://bulkpharm.mallinckrodt.com/_attachments/msds/oxone.htm Oxycodone hydrochloride MSDS]</ref>), dihydrocodeine bitartrate &c. have a higher solubility in water at lower temperatures than paracetamol<ref>[http://bulkpharm.mallinckrodt.com/_attachments/msds/PARAC.htm Acetaminophen/Paracetamol MSDS]</ref> and ibuprofen<ref>[http://bulkpharm.mallinckrodt.com/_attachments/msds/IBUPR.htm Ibuprofen MSDS]</ref>. The more the water cools, the less paracetamol and ibuprofen the solution will retain in proportion to the opioid salts.
==References==
{{Reflist}}
==See also==
* [[Hot water extraction]]
* [[Codeine]]
==External links==
* Cone EJ. "Ephemeral profiles of prescription drug and formulation tampering: Evolving pseudoscience on the Internet". Drug Alcohol Depend. 2006;83 Suppl 1:S31-9. [http://www.erowid.org/references/refs_view.php?A=ShowDocPartFrame&ID=6660&DocPartID=6173 full text]
[[Category:Homogeneous chemical mixtures]]
[[Category:Opioids]]
[[Category:Solutions]]
[[sv:CWE]]