Purity of Aspirin
- To research, using various sources, the history of aspirin, its use in medicine, methods of synthesizing it and of measuring its purity
- To compare the % purity of a branded aspirin tablet with a generic aspirin tablet
- To compare 2 methods of composition analysis of the two types of aspirin
The history of Aspirin 1
400BC, Greece- Hippocrates recommended the use of a brew made with willow leaves to help with the pain of childbirth.
1763, England- Edward Stone, a clergyman, having read a paper regarding the use of Willow bark on malaria (Agues), collected observations from around the country on its effects in relieving the fever that comes with malaria.
1830’s- a Scottish physician found that willow bark relieved symptoms of acute rheumatism.
1840’s- Organic Chemists identified the active ingredient in willow bark to be salicin.
1874, Dresden, Germany- Salicylic acid was first made and sold as a pain-killer, but it caused severe irritation of the mouth, gullet and the lining of the stomach.
Salicylic acid (2-Hydroxybenzoic acid)
1875- Chemists made sodium salicylate for doctors to try on patients. It was found to have fewer digestive side-effects, and still worked to reduce pain, however it tasted horrible and caused rheumatism patients to vomit.
1890’s, Germany- Felix Hoffman of Bayer pharmaceuticals made aspirin with good medicinal properties, low membrane irritation and a reasonable taste.
The name ‘aspirin’-
a-acetyl, as the systematic name for aspirin was acetylsalicylic acid
spir- spirea plant which yields salicin
Asprin (2-Ethanoyloxybenzenecarboxylic acid)
1898- Aspirin was sent for clinical trials, Bayer manufactured the medicine and patented the process.
1915- The British needed aspirin in WW1, but since it was made by the Germans, the government offered a £20,000 reward to whoever could develop a workable manufacturing process. George Nicholas, a Melbourne pharmacist, did this and called his tablet ‘Aspo’.
1982- John Vare, who was that year receiving a Nobel prize for his work on prostaglandins, discovered aspirin and some other pain-killers/anti-inflammatory drugs to inhibit the key enzyme in the prostaglandin pathway, thereby stopping the production of some prostaglandins that cause pain and inflammation.
Now types of aspirin are made all over the world each year, and it is not only used as a painkiller but is also effective in reducing the incidence of heart disease.
Chemistry of aspirin and its use in medicine 2
* Chemical structure of acetylsalicylic acid
| acetylsalicylic acid
| 2-acetoxybenzoic acid
| 136°C (277°F)
| 140°C (284°F)
* Aspirin is an aromatic acetate
-aromatic: organic chemical made by natural sources containing a benzene ring -its structure also includes an ester group and a carboxylic group attached to adjacent carbon atoms on the benzene ring
* Aspirin is a derivative of salicylic acid
-salicylic acid: C7H6O3, Mr: 138
-contains a phenol group, the hydroxyl of which is...
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