What Is Papaverine?
Papaverine is an opium alkaloid used in medicine.
Its IUPAC name is 1-[(3,4-dimethoxyphenyl)methyl]-6,7-dimethoxyisoquinoline, also known as 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)isoquinoline and Robaxapap.
Uses of Papaverine
Papaverine, present in opium at 0.8-1%, has a weaker central action and anesthetic effect compared to morphine. Its hydrochloride form relaxes visceral and vascular smooth muscles, alleviating abdominal pain by reducing tension in the gastrointestinal tract. It is effective for spasms related to gastritis, bile duct, and gallbladder diseases, and improves blood circulation by relaxing vascular smooth muscles, aiding in conditions like acute arterial and pulmonary embolisms, and circulation disorders.
Properties of Papaverine
With a chemical formula of C20H21NO4 and a molecular weight of 339.39, papaverine is a white crystalline solid. It has a melting point of 147°C, a density of 1.337 g/ml, and is registered under CAS number 58-74-2. Light and moisture sensitive, it is soluble in alcohol, ether, acetone, and benzene, with limited solubility in chloroform, petroleum ether, and water (35 mg/L at 17°C). Its pH range is 2.0 to 2.8, with a pKa of 8.07, indicating a relatively weak acid.
Types of Papaverine
Papaverine hydrochloride (CAS Registration Number: 61-25-6) is a common form, a white crystal or powder with a molecular weight of 375.85, melting point of 220-225°C, soluble in alcohol and chloroform, and water solubility of 25mg/ml.
Other Information about Papaverine
1. Manufacturing Method of Papaverine
Papaverine is produced mainly through chemical synthesis, involving the Schotten-Baumann reaction for amide synthesis, followed by cyclization through the Bischler-Napieralski reaction, and mild dehydrogenation to synthesize papaverine.
2. Papaverine Side Effects
Reported side effects include constipation, dizziness, hot flashes, dry mouth, and palpitations. It is considered safe with no serious side effects but should be used cautiously by glaucoma patients due to potential increases in intraocular pressure.
3. Papaverine Legal Information
Papaverine is regulated under national dangerous goods shipping, storage regulations, and aviation law, classified as a poisonous substance.
4. Handling and Storage Precautions
Avoid contact with strong oxidizing agents. Use protective clothing, gloves, goggles, and a local exhaust system when handling. In case of fire, extinguish using appropriate means. Store in a tightly closed glass container away from light in a cool, well-ventilated area.