Description

Technical Parameters

Introduction

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product-1400-1400

Products Description

#### **Introduction**

Procaine, chemically known as 2-diethylaminoethyl para-aminobenzoate, is the first synthetic local anesthetic developed by German chemist Alfred Einhorn in 1905 to replace highly toxic cocaine. Its hydrochloride form (Procaine Hydrochloride) is widely used in the medical field with advantages such as high safety and low cost. This article systematically introduces its chemical properties, classification, application and market status.

### **1. Chemical structure and physicochemical properties**

- **Molecular formula**: C₁₃H₂₀N₂O₂

- **Molecular weight**: 236.31 g/mol

- **Structural formula**: Para-aminobenzoic acid and β-diethylaminoethanol are connected by an ester bond, and it has both hydrophilicity and fat solubility.

- **Physical properties**:

- Free base: white crystalline powder, melting point 61°C, slightly soluble in water, easily soluble in organic solvents.

- Hydrochloride (Procaine HCl): CAS No. 51-05-8, melting point 156°C, easily soluble in water (1:1), pH 5.0-6.5.

- **Chemical stability**: The ester bond is easily hydrolyzed, especially in alkaline or high temperature environments, and needs to be stored away from light.

### **2. Classification and main types**

#### **Classification by chemical form**

1. **Procaine Base**

- CAS No.: No independent number (usually mainly hydrochloride).

- Use: As an intermediate to synthesize other derivatives.

2. **Procaine Hydrochloride**

- CAS No.: 51-05-8

- Purity: Pharmaceutical grade ≥99%, in line with USP/EP standards.

#### **Classification by application field**

- **Pharmaceutical grade**: used for injection, surface anesthetic.

- **Industrial grade**: used as an intermediate to produce procaine penicillin.

- **Scientific research grade**: high purity (≥99.5%), used for pharmacological research.

### **3. Advantages and characteristics**

- **Low toxicity**: LD₅₀ (rat oral) 500 mg/kg, significantly lower than cocaine.

- **Fast metabolism**: hydrolyzed by plasma esterase, short action time (30-60 minutes), reducing systemic toxicity.

- **Cost-effectiveness**: simple synthesis process, easy to obtain raw materials, lower price than lidocaine.

- **Versatility**: has both anesthetic and vasodilation effects, suitable for a variety of clinical scenarios.

### **4. Application field**

#### **Medical field**

- **Local anesthesia**: infiltration anesthesia, nerve block (concentration 0.25%-2%).

- **Spinal anesthesia**: Used in combination with epinephrine to prolong the duration of effect.

- **Dental**: Analgesia for gum surgery and tooth extraction.

#### **Cosmetics and anti-aging**

- **Anti-wrinkle products**: Reduce dynamic wrinkles by inhibiting muscle contraction.

- **Soothing ingredients**: Used for sensitive skin care to relieve tingling.

#### **Scientific research applications**

- **Neurobiology**: Study inhibitor models of sodium ion channels.

- **Drug carrier**: Used in the development of sustained-release preparations.

### **5. CAS number and product specifications**

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### **6. Synthesis method and process**

**Classic synthesis route**:

1. **Esterification reaction**: p-aminobenzoic acid reacts with thionyl chloride to form acyl chloride.

2. **Condensation reaction**: Acid chloride and β-diethylaminoethanol are esterified under alkaline conditions.

3. **Salting**: Free base is neutralized with hydrochloric acid and purified by crystallization.

**Process optimization**: Microwave-assisted synthesis is used to increase the yield to more than 85%.

### **7. Safety and toxicology**

- **Side effects**: Allergic reactions (not suitable for patients sensitive to p-aminobenzoic acid), transient hypotension.

- **First aid measures**: In case of overdose, respiratory support is required, and intravenous barbiturate antagonism is given.

- **Storage conditions**: Avoid light, keep cool (2-8°C), and relative humidity <60%.

### **8. Market status and suppliers**

- **Major manufacturers**: China (such as Hengrui Medicine), India (Sun Pharma), Europe (BASF).

- **Price trend**: The global average price in 2023 is $80-120/kg, affected by the fluctuation of raw materials (p-nitrobenzoic acid).

- **Market demand**: Annual growth rate of 3.5%, with rising demand in emerging markets (Southeast Asia).

### **Conclusion**

As a classic local anesthetic, procaine continues to play an important role in the medical and industrial fields due to its safety and economy. In the future, with the development of sustained-release preparations and compound drugs, its application prospects will be further expanded. Manufacturers need to pay attention to green synthesis processes and compliant production to adapt to global regulatory trends.