Physical and chemical properties of acetylsalicylic acid

Aspirin [Aspirin, 2 – (acetoxy) benzoic acid, also known as acetylsalicylic acid [98]] is a white crystalline or crystalline powder, odorless or slightly sour, slightly soluble in water, easily soluble in ethanol, soluble in ether and chloroform, and the aqueous solution is acidic. This product is a derivative of salicylic acid. After nearly a hundred years of clinical application, it has proved to be effective in relieving mild or moderate pain, such as toothache, headache, neuralgia, muscle aches and dysmenorrhea. It is also used to reduce fever and treat rheumatic pain in febrile diseases such as colds and flu. In recent years, it has been found that aspirin can inhibit platelet aggregation and prevent thrombosis. It is clinically used to prevent the formation of thrombosis after transient ischemic attack, myocardial infarction, artificial heart valve and venous fistula or other operations.

Physical and chemical properties of acetylsalicylic acid

Properties: white acicular or tabular crystal or crystalline powder. Odorless, slightly sour.

Molecular chemical formula: C9H8O4

Molecular structure formula: CH3COOC6H4COOH

Molecular relative mass: 180.16

CAS No. 50-78-2

Melting point: 136-140 ℃

Boiling point: 321.4 ° C at 760 mmHg

Flash point: 131.1 ° C

Water solubility: 3.3 g/L (20 ℃)

Steam pressure: 0.000124mmHg at 25 ° C

Solubility: slightly soluble in water, soluble in ethanol, ether, chloroform, also soluble in strong alkaline solution, and decomposed at the same time.

Safety instructions: S26: In case of contact with eyes, immediately wash with plenty of water and send to a doctor for treatment; S36/37/39: Wear appropriate protective clothing, gloves and use protective glasses or masks.

Dangerous goods sign: Xn: hazardous substance

Risk category code: R22: Harmful if swallowed; R36/37/38: Irritating to eyes, respiratory tract and skin.

Transport No. of dangerous goods: UN1851

InChI code: 1/C9H8O4/c1-6 (10) 13-8-5-3-2-4-7 (8) 9 (11) 12/h2-5H, 1H3, (H, 11,12)

Research and development history of acetylsalicylic acid

As early as 1853 in Shire, Frederick Gerhardt synthesized acetylsalicylic acid (acetylated salicylic acid) from salicylic acid and acetic anhydride, but failed to attract people’s attention. In 1897, German chemist Felix Hoffman made another synthesis and treated his father’s rheumatoid arthritis with excellent effect. In 1897, Bayer, Germany, first synthesized the main substance of aspirin.

Aspirin came into the market in 1898, and it was found that it also had the effect of anti platelet aggregation, so it aroused great interest again. Aspirin and other salicylic acid derivatives were melt esterified with hydroxyl containing polymers such as polyvinyl alcohol and cellulose acetate to make them macromolecular. The anti-inflammatory, antipyretic and analgesic properties of the obtained products were longer than those of free aspirin.

By 1899, Bayer had sold the drug to the world under the trademark Aspirin.

By 2015, aspirin has been used for a hundred years, and has become one of the three classic drugs in the history of medicine. Up to now, it is still the most widely used antipyretic, analgesic and anti-inflammatory drug in the world, and also the standard preparation for comparing and evaluating other drugs. It has antithrombotic effect in vivo. It can inhibit the release of platelets and inhibit platelet aggregation, which is related to the reduction of TXA2 production. It is clinically used to prevent the attack of cardiovascular and cerebrovascular diseases.

Indications of acetylsalicylic acid

Aspirin can inhibit platelet aggregation, so the indications of aspirin enteric coated tablets are as follows:

1. Reduce the incidence risk of suspected patients with acute myocardial infarction

2. Prevent recurrence of myocardial infarction

3. Secondary prevention of stroke

4. Reduce the risk of transient ischemic attack (TIA) and its secondary stroke

5. Reduce the risk of patients with stable and unstable angina pectoris

6. After arterial surgery or intervention, such as percutaneous transluminal coronary angioplasty (PTCA), coronary artery bypass (CABG), carotid endarterectomy, and arteriovenous shunt

7. Prevention of deep vein thrombosis and pulmonary embolism after major surgery

8. Reduce the risk of myocardial infarction in patients with cardiovascular risk factors (family history of coronary heart disease, diabetes, dyslipidemia, hypertension, obesity, smoking history, people over 50 years old).

Other uses:

Usage 1: Antipyretic and analgesic, used for fever, pain and rheumatoid arthritis.

Use 2: It is the earliest, broadest and most common antipyretic and analgesic anti rheumatic drug. It has many pharmacological effects, such as antipyretic, analgesic, anti-inflammatory, anti rheumatism and anti platelet aggregation. It has a rapid and definite effect. It is easy to diagnose and treat with overdose, and rarely has allergic reactions. It is commonly used for cold and fever, headache, neuralgia, arthralgia, muscle pain, rheumatic fever, acute endophytic arthritis, rheumatoid arthritis and toothache. It is listed in the National Essential Drug Catalogue. Acetylsalicylic acid is also an intermediate of other drugs.