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Cinchocaine Base Powder CAS 85-79-9 - Top China Suppliers & Factory for Local Anesthetic Drug Production
Definition
ChEBI: A monocarboxylic acid amide that is the 2-(diethylamino)ethyl amide of 2-butoxyquinoline-4-carboxylic acid. One of the most potent and toxic of the long-acting local anesthetics, its parenteral use was restricted to spinal anesthesia. It is now generally only used (usually as the hydrochloride) in creams and ointments and in suppositories for temporary relief of pain and itching associated with skin and anorectal conditions.
Manufacturing Process
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1
A benzene solution of 2.2 parts of α-chloro-γ-quinoline-carboxylic acid chloride is gradually mixed, while cooling, with 2.3 parts of unsymmetrical diethylethylenediamine. When the reaction is at an end the solution is washed with water and the new base extracted by means of hydrochloric acid. The base is precipitated by means of sodium carbonate and extracted with benzene. The solvent is distilled and the base recrystallized from petroleum ether. The α-chloro-γ-quinoline-carboxylic acid diethyl-amino-ethylene amide forms colorless lamina crystals of melting point 74°C. With acids the base forms neutral salts soluble in water.
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2
A solution of 2.5 parts of sodium in n-butylalcohol is boiled with 30 parts of α- chloro-γ-quinoline-carboxylic acid diethyl-amino-ethylene-amide in a reflux apparatus, and when the reaction is over the excess of butylalcohol is distilled. The remaining base is taken up with ether; the solution is washed with water and dried. The solvent is then distilled. The α-n-butoxy-γ-quinoline. carboxylic acid diethyl-amino-ethylene-amide forms as colorless crystals, after recrystallization from petroleum ether melting point of it 64°C.
Note: In practice it is usually used as hydrochloride.
General Description
Articaine has a secondary nitrogen with a pKa of 7.8. It contains an aromatic thiophene ring bioisostere of the phenyl ring found in most other amide anesthetics. The log P of a benzene ring is 2.13 and the thiophene ring log P is 1.81, thus the thiophene ring is more hydrophilic than a phenyl ring. Although the thiophene ring has less lipid solubility than a phenyl ring, articaine is a lipid-soluble compound due to the propylamine, the branched methyl and the substitutions on the thiophene ring. The onset of action of articaine is similar to lidocaine’s onset of action.
Important Tips
HCl soluble in water, base insoluble in water. (Some Base dissolves in hot water!)
Clinical Use
Articaine is available in a 4% solution with epinephrine for use in infiltration and nerve block anesthesia. Articaine is metabolized rapidly via plasma and tissue carboxyesterase to its primary metabolite, the inactive, water-soluble carboxylic acid. Approximately 40% to 70% of articaine administered epidurally is metabolized to the carboxylic acid, articainic acid. Approximately 4% to 15% of the articainic acid undergoes glucuronide conjugation and only 3% of the dose is recovered unchanged in the urine. The rapid plasma metabolism and reported inactivity of the carboxylic acid metabolite make articaine a potentially safer anesthetic agent when multiple or large doses are necessary.
Uses
Cinchocaine is a local anesthetic, used for Na+ channel blocker.
Anesthesia Strength comparison
Local anesthesia strength: the anesthesia effect of some base is stronger than hcl.
Tetracaine
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Lidocaine
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Benzocaine
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Procaine
Details
Frequently Asked Questions
What is Cinchocaine (Dibucaine) primarily used for?
Cinchocaine is a potent, long-acting local anesthetic that acts as a Na+ channel blocker. It is commonly used in creams, ointments, and suppositories to provide temporary relief from pain and itching associated with skin and anorectal conditions.
How does the solubility of the anesthetic base compare to its hydrochloride (HCl) salt?
Generally, the hydrochloride (HCl) salt form is highly soluble in water, whereas the free base form is insoluble in cold water. However, some free bases can dissolve in hot water.
Why is Articaine considered a lipid-soluble compound despite having a hydrophilic thiophene ring?
Although its thiophene ring has lower lipid solubility (log P of 1.81) compared to a phenyl ring (log P of 2.13), Articaine remains lipid-soluble due to the presence of its propylamine group, branched methyl group, and specific substitutions on the thiophene ring.
What makes Articaine a potentially safer anesthetic agent for larger doses?
Articaine is metabolized very rapidly by plasma and tissue carboxyesterase into its primary metabolite, articainic acid, which is inactive and water-soluble. This rapid metabolism and the inactivity of the metabolite lower the risk of systemic toxicity.
How does the anesthetic strength compare among common local anesthetics?
The relative local anesthesia strength follows the order: Tetracaine > Lidocaine > Benzocaine > Procaine. Additionally, the anesthetic effect of the free base form of these substances is often stronger than their hydrochloride (HCl) salt form.