Application of powdered activated carbon in pharmaceutical industry

Activated carbon is widely used in pharmaceutical industry. It can be found in chemical synthetic drugs, biological agents, vitamins, hormones, injections, large infusion and so on. Moreover, activated carbon can also penetrate into medical products or be directly used in medical drugs.

1、 Vitamins

1. vitamin A

Vitamin A can be separated from carotene or vitamin D can be separated by active carbon. The concentrate from cod liver oil can be dissolved in heptane, filtered by active carbon adsorption column, and then washed with fresh heptane, then vitamin D will be eluted first, followed by vitamin A.

2. vitamin C

Vitamin C is ascorbic acid, which is easily oxidized to dehydroascorbic acid and is a strong reducing agent.

In industry, sorbitol is used as raw material, but the crude product should be decolorized by activated carbon before recrystallization. Decolorization of crude vitamin C solution is a very important procedure. It is said that it is important because vitamin C is too easy to be oxidized into dehydroascorbic acid, reducing the quality of finished products. This conversion degree is often closely related to the type of carbon, so the selection of carbon is particularly critical, because the active carbon itself is the catalyst to promote the conversion, such as the carbon with nitrogen element has strong oxidation ability, and only the carbon with oxygen functional group has reducibility. In addition, the atmosphere of the medium is also crucial when decolorizing. When decolorizing in the solution, nitrogen filling or some reducing agents are sodium sulfide and sodium thiosulfate impregnating the activated carbon can also weaken the oxidation of ascorbic acid, and the activated carbon can also be made into wet carbon for use, because the air in the carbon pores can be discharged after the activated carbon is immersed in water, but it is better to choose a product called "antioxidant activated carbon". In addition to the properties of the carbon, the impurities in the carbon are also very important, especially the iron content is very low, preferably less than 100mg / kg. In recent years, granular activated carbon (GAC) has been developed and used in adsorption tower for continuous decolorization.

3. vitamin D

Vitamin D was adsorbed by active carbon from autolysis yeast, and then washed by acetic acid.

4. Vitamin g (riboflavin)

Vitamin g concentrate was prepared from whey with adsorbent. The vitamins in whey are first absorbed by clay at low temperature, and then washed out by hot water. The vitamins in the washing solution are adsorbed by activated carbon, then desorbed by ethanol benzene mixture, and finally evaporated to get vitamin G.

5. vitamin H

Vitamin H (which was later proved to be a mixture of vitamin B6 and vitamin B5) was enriched 60-90 times from rice bran with activated carbon. The success of this process depends on several steps in advance. The acidified rice bran extract is used to absorb vitamin B1 with clay, the filtrate is neutralized and evaporated to dryness, then the solid dry matter is extracted with anhydrous ethanol, and the extract is diluted with water and then absorbed with active carbon. Finally, use n-butanol or other suitable solvent to wash out the vitamin H on the activated carbon.

6. Vitamin B1 (thiamine)

It plays an important role in maintaining the normal glucose metabolism of human body and is also an anti neuritis factor. Yeast was extracted with water, neutral lead acetate was added to precipitate some impurities. After filtration, the filtrate was treated with barium hydroxide to precipitate the colloid. Excess barium hydroxide was removed with sulfuric acid, and other impurities in the solution were removed with mercury sulfate. Active carbon was added to the filtrate to adsorb thiamine. Finally, thiamine was washed with 50% ethanol solution of 0.1mol/l hydrochloric acid. In recent years, furathiamine with similar structure to vitamin B1 has also been synthesized, also known as "new B1".

2、 Antibiotics

1. penicillin G

In the early stage, the method of extracting penicillin was adsorption with active carbon and washing with organic solvent. Later, it was also extracted directly with various solvents. At that time, activated carbon adsorption was an important method, but it was later replaced by other methods.

2. streptomycin

In 1944, Waksman extracted antibiotics from the culture medium of Streptomyces, called streptomycin. The crude products can be obtained by using activated carbon adsorption and ion exchange. Pure stre ptomyces griseus was inoculated on a sterile medium, which was exposed to air in sterile condition and fermented for several days at 25-30 ℃. Filter the culture gravy, adjust the acidity of the filtrate to pH = 7 (because only at this pH can the activated carbon absorb streptomycin), and then add the activated carbon. The addition amount of activated carbon should be strictly controlled. If the addition amount is not enough, the adsorption will not be complete, but if the amount is excessive, the washing output will be reduced. Filter to separate the carbon from the solution, wash the carbon cake with ethanol to remove the impurities left on the carbon, and then wash the streptomycin off the carbon with the acidified methanol (the active carbon in the acid environment cannot absorb streptomycin). After neutralizing the washing solution, the conditions were strictly controlled, and the crude product with purity of 25% - 30% was obtained by vacuum evaporation. At last, we use the property that the activated carbon does not adsorb streptomycin but can adsorb impurities when pH = 2 to refine. We use the property that the activated carbon can adsorb streptomycin when pH = 7 to separate it. The streptomycin on the carbon is washed with dilute acetone adjusted to pH = 2.5, and then the pure product is condensed out.

Three, hormone

1. insulin

The initially purified insulin solution was adjusted to pH 2.5 with hydrochloric acid, and then added with activated carbon. After 12 hours of contact, the solution was filtered, and the carbon filter cake was washed with water. Then, the solution was treated with 60% ethanol solution containing 5% acetic acid to elute some impurities, but it had no effect on insulin. after