Procaine benzylpenicillin (penicillin G procaine, CAS 54-35-3) is the procaine salt of benzylpenicillin, supplied here as a sterile, micronized, lecithin-coated grade (approx. 1% lecithin) for injectable pharmaceutical and veterinary use. It provides sustained penicillin G levels and is manufactured to comply with Ph. Eur. 12th Edition.
Specifications (Ph. Eur. 12)
| Parameter | Value |
|---|---|
| Appearance | White or almost white crystalline powder, slightly hygroscopic, slightly soluble in water, sparingly soluble in ethanol (96%) |
| pH | 5.0-7.5 (50 mg / 15 ml water) |
| Impurity A | 0.024% max |
| Impurity B (sum of isomers) | 0.4% max |
| Impurity C (sum of epimers) | 0.4% max |
| Impurity D | 0.2% max |
| Impurity E | 0.2% max |
| Impurity F | 0.5% max |
| Impurity G | 0.5% max |
| Impurity H | 0.5% max |
| Impurity I | 0.5% max |
| Impurity J | 0.5% max |
| Specified impurity I | 0.2% max |
| Any other impurity | 0.2% max |
| Total impurity 1 | 2.0% max |
| Total impurity 2 | 2.0% max |
| Water | 2.8-4.2% |
| Residual solvents: n-Butanol | 5000 ppm max |
| Residual solvents: Ethyl acetate | 5000 ppm max |
| Bacterial endotoxins | 0.10 IU/mg max |
| Sterility | Meets the requirements |
| Assay: Procaine | 39.0-42.0% (anhydrous substance) |
| Assay: Procaine benzylpenicillin | 96.0-102.0% (anhydrous substance) |
| Lecithin-coated content | 0.5-1.5% |
| Particle size | 50% <8 μm (customer requirement: 90% <25 μm) |
Conclusion: Complies with Ph. Eur. 12th Edition standards.
Applications
- Injectable penicillin G sustained-release formulations for veterinary medicine (cattle, swine, sheep and poultry).
- Pharmaceutical-grade sterile API for human injectable penicillin products.
- The micronized, lecithin-coated grade improves suspension stability and syringeability for long-acting formulations.
Storage and Packaging
Store in a tightly sealed container, protected from light, in a cool, dry place. Standard packaging: sterile, sealed containers (e.g. 5-25 kg) as required for aseptic processing.
FAQ
What is lecithin-coated procaine penicillin? A micronized sterile grade where particles are coated with about 1% lecithin to improve wettability, suspension stability and injection handling of long-acting penicillin formulations.
Is this grade sterile? Yes – sterility is tested and meets Ph. Eur. requirements, suitable for aseptic filling of injectables.




