Extraction Technique: Waterless A/Bby geezmeister (format & minor edits by metanoid)
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Waterless A/B extraction of pseudoephedrine from tablets
Abstract of procedure:
1)If using 30 mg pills with red coating, remove the red coating. Grind pills to powder form. Use a morter and pestle after coffee grinder; texture should be a fine powder and few coffee grinders get the pills fine enough by themselves.
2) The powdered pill mass should first be soaked in a non-polar solvent. Choice of solvent is dictated by the presence of povidone and/or polyethylene glycol. If povidone is present, mineral turpentine is the solvent of choice; alternatives include xylene, tolulene, mineral spirits. Suggested time: twelve hours. If povidone is not present but polyethylene glycol is present, soak in non-polar solvent for at least six hours. Recommended solvent: xylene, tolulene, mineral spirits. Decant non-polar solvent.
3) Rinse pill mass with dried acetone, discard acetone. If the pills contain an antihistamine, place pill mass in pyex dish, cover with two to three times its volume in dried acetone, bring temperature up slowly with hotplate to a steady gentle boil with constant ventilation. No open flame or ignition source may be used. Stir boiling acetone continuously for five minutes, remove from heat, decant acetone. Spread pill mass and allow to dry to complete dryness.
4) Weigh out one gram of NaOH for each gram of available pseudoephedrine in the pill mass. Weigh out one gram of NaCl for each gram of available pseudoephedrine (rock salt is recommended). Combine and grind in coffee grinder to fine powder. Take care to avoid inhalation of powdered NaOH! Mix the combined salt and sodium hydroxide with the dry pill mass and stir with a glass rod until the mixture is evenly and thoroughly mixed.
5)With the pill mass/ sodium hydroxide/ salt mixture in a pyrex beaker of sufficient depth to allow the addition of three times the pill mass volume of non-polar solvent, add very dry isopropyl alcohol in small quantities while mixing the mass with a glass rod; continue adding alcohol and stirring until the pill mass has the consistency of a thin paste. The pill mass should heat slowly during this step. At no time should the mass become too hot to hold comfortably. If the heat rises quickly and beyond comfortable temperature to hold, add non-polar solvent immediately. As long as the temperature does not make a quick surge, work the pill mass for at least ten minutes to insure all portions of the pill mass have been exposed to the base. You will observe the color change of the pill mass, most usually to a medium yellow or light tan/brown shade. This is expected. Dark brown indicates the presence of excess water but will not impede the process.
6) Add three times the volume of the pill mass with non-polar solvent. Xylene is recommended. Mix this with the paste very thoroughly, recommended for at least fifteen minutes. Allow to settle, decant the non-polar solvent. Repeat this step twice. The amount of mixing and the time period may be shortened for the last two non-polar soaks. Combine the three volumes of non-polar solvent used to extract the freebase pseudoephedrine.
7) Wash the non-polar solvent with warm distilled water wash, cool distilled water wash, and a third warm water wash. Continue washing until the washes are clean. After the third wash, monitor the pH and do not allow it to fall below pH 9. If necessary to remove excess sodium ions, do a NaOH wash of the nonpolar with a 20% NaOH solution.
8) Extract the pseudoephedrine from the non-polar solvent by gassing or by aqueous HCl addition and evaporation to near dryness, followed with an acetone "flash."
9) Rinse the collected pseudoephedrine in dry acetone. Dissolve in hot dry isopropyl alcohol and recrystalize with dry acetone as a second solvent. Repeat the recrystalization.
Notes and comments:
1) Pill selection: this process was developed with generic antihistamine tablets with 60 mg pseudoephedrine and 2.5 mg tripolidine. It also is effective with pseudoephedrine sulphate antihistamine tablets with cloropheneramine maleate, and changes the form to the salt form for the reaction. Name brand and generic 120 mg and 240 mg time release pseudoephedrine tablets may be extracted with the process. Yields for the above average 60- 66 percent of available pseudoephedrine hydrochloride by weight. Extraction process yields very clean pseudoephedrine HCl. If the pills are dry matrix formulation such as the time release 120 mg caplets, it is very important that every solvent used be as dry as possible and that the pill mass not be exposed to excess moisture or allowed to remain exposed and uncovered.
2) The presoak in non-polar solvent is to remove povidone and mineral turpentine is recommended. Alternatives are soaks in xylene, tolulene, mineral spirits. Minimum twelve hour soak for any solvent but mineral turpentine. If povidone is not listed and you are familiar with the pills and have not encountered povidone in them even though unlisted, a soak in any of the other suggested non-polar solvents is done to remove polyethylene glycol. Six hours is sufficient; shorter times may be effective but have not been tested by the author. PEG should be soluble in any of the nonpolar solvents, but if the pills are the 120 time release formulation (or the "dry matrix" formulation) the author strongly suggests xylene be used.
3) The acetone rinse is to rid the pill mass of the non-polar solvent. The following acetone boil is to remove tripolidine or chloropheneramine maleate. If there are no antihistamines present in the formula, the acetone boil is unnecessary and should not be done. Do not boil the pill mass with the solvent, or with the solvent and acetone combined. Rinse the solvent and then use fresh acetone to boil. Yield seems to be better is the entire pill mass is allowed to dry thoroughly before the addition of base. Drying in the microwave on less than full power is effective, although not particularly recommended. Drying in an electric oven at low temperature, not to exceed 150 degrees F if also effective to dry the pill mass.
4) If the pill mass is in the least clumpy or hard, grind it to powder again before proceeding. NaOH may be used to base. Gram per gram is probably an excess of NaOH, but it does effect the basing. Sodium carbonate has been used with good success and it provides fewer contaminants to the non-polar solvent that need to be washed out. Baking soda baked completely dry-- 350 degrees for thirty minutes in a shallow dish should be sufficient, yields sodium carbonate. pH Down at the pool store is sodium carbonate and may also be used for the process. Salt is recommended as an addition to the lye as it provides a moisture absorbing substance to help prevent the lye from absorbing moisture immediately on powdering. Lye can be used without grinding it; powdered NaOH seems to give better performance.
5) The selection of solvents to mobilize the HCl is one of choice. On the antihistamine type pills, MeOH may be used, but is not recommended. Very dry ISO alcohol is one recommendation, although dry acetone seems to work very well. If the pills are time release or dry matrix formulation, dryness is essential to yield. Dry acetone is highly recommended. The addition of the solvent should be a little at a time, working the pill mass until a slightly thin paste is achieved. Water, including moisture in alcohol or acetone, will tend to speed the basing process up and if NaOH is used it can become hot too quickly and damage the pseudoephedrine. Care should be taken to select dry solvents. Working the mass thoroughly is thought to be important to yield. Too much alcohol can impede the a/b process, and the amount used should be carefully tailored to avoid making the pill mass runny and diluting the non-polar solvent with alcohol.
6) Xylene is the author's preferred non-polar solvent for extracting the freebase pseudoephedrine as it is unlikely to contain any significant amount of water straight from the can, or even after having been used. It is considered to be the solvent of choice for dry matrix formulations. Tolulene and Mineral Spirits have been used with equivalent success. Naptha is not a recommended solvent for this purpose.
7) The washes will rid the non-polar solvent of any color they aquire from the pill mass and excess sodium ions. Wash until clean. Save the water washes to check for pseudo freebase that may hitch a ride in the water. It can happen.
Advantages: works with most pills; safer than solvent boiling techniques; fewer solvents used; less odor; pseudoephedrine HCl obtained is very clean and has fewer impurities that affect the reaction, contaminate the red phosphorous, or contribute to yield loss.
Disadvantages: complex for those unfamiliar with a/b process; risk of damage to the pseudoephedrine during the basing process; low yields if done improperly or too much alcohol used; may allow polyethylene glycol or povidone to be extracted with the pseudoephedrine if proper soaking is not done; some report limited yields with the process.
Known to be effective with pills containg the following ingredients:
Pseudoephedrine HCl 60 mg
patent no. 5098715
Pseudoephedrine HCl 60 mg
may also contain:
Pseudoephedrine Hcl 120 mg
Pseudoephedrine Hcl 240 mg