Is the project of extracting heparin sodium from pig small intestine feasible?
Heparin sodium is an important biochemical drug, clinically used to treat acute myocardial infarction and viral hepatitis. Combined with ribonucleic acid, it can increase the efficacy against hepatitis B. Combined with chemotherapy, it helps prevent the metastasis of cancer cells. In addition, it also has the effect of preventing thrombosis. The production of heparin sodium falls short of demand, and the gap in the international market is extremely large. The intestinal mucosa from about 2000 pig small intestines after processing the casings can produce 1 kg of heparin sodium, worth about 22000 yuan. Therefore, using this by-product, pig small intestine mucosa, to produce heparin sodium has considerable value, with very obvious economic and social benefits, and broad prospects.
The specific process is as follows: Production process
1. Extraction. Add 5% sodium chloride solution to the mucosa scraped from pig casings, enough to completely submerge the mucosa. Use sodium hydroxide solution to adjust the pH of the solution to 9.0-9.5, and soak for about 10 hours. The key to this step is that the intestinal mucosa fluid must be fresh and have a moderate water content (total solids content of 6%-7%).
2. Adsorption. Cool the above solution to about 50°C, and remove the oil and impurities floating on top. Add treated 714 resin, with the resin amount being 4%-6% of the mucosa. Stir and adsorb for 8-10 hours, correcting the pH value at any time to keep it between 9.0 and 9.5. Then filter with a 70-mesh to 80-mesh nylon mesh bag, filter out the resin, and discard the filtrate.
3. Washing. Rinse the resin that has adsorbed heparin sodium with water until the wash liquid becomes clear, then drain. Then place the resin in a bucket, add 1 times its volume of 1.4 mol/L sodium chloride solution, stir and wash for 1 hour, and drain. Then repeat washing twice with 1 times its volume of 1.2 mol/L sodium chloride solution under the above conditions and drain the resin. In the last washing, it is best to use refined salt water.
4. Elution. Stir and elute the resin with 5 mol/L sodium chloride for 2 hours, with the amount of sodium chloride being half the amount of the resin. Then filter and collect the filtrate. Stir and wash the resin twice more with 3 mol/L sodium chloride solution, 24 hours each time (the amount of sodium chloride solution is still half the amount of the resin), filter, and collect the filtrate.
5. Precipitation. Combine the three filtrates, adjust the pH to 7.2-7.4, add 95% ethanol solution and stir evenly, and let stand to precipitate. The amount of ethanol used varies with the four seasons: in winter, the ratio of filtrate to ethanol is 1:1; in spring, 1:1.3; in summer and autumn, about 1:1.5. The precipitation time is more than 24 hours but not more than 48 hours, and it is ready when obvious white particles precipitate out and separation occurs.
6. Dehydration and drying. Remove the ethanol liquid floating above the heparin sodium precipitate by siphon method. Wash the precipitate repeatedly several times with 95% ethanol, collect the precipitate, vacuum filter, and suck dry, then repeatedly dehydrate 2-3 times with acetone, with the ratio of acetone to heparin sodium being 1:3. After sucking dry, dry at 60°C or vacuum dry for more than 48 hours to obtain crude heparin sodium.
7. Refining: Dissolve the obtained crude product with 2% sodium chloride solution to prepare about a 10% heparin sodium solution. Then adjust the pH to 8, add potassium permanganate at 4% or 30% hydrogen peroxide for decolorization treatment, and remove basic and acidic proteins. Filter and adjust the pH to 6.5, then precipitate heparin sodium with 0.9 times 95% ethanol, filter out the precipitate, and vacuum filter to dryness. Then dehydrate with anhydrous ethanol and acetone, finally treat once with ether, and vacuum dry to obtain refined heparin sodium.