Buying procaine benzylpenicillin (CAS 54-35-3) as a sterile micronized API means reading a pharmacopoeia-grade COA correctly – assay, impurity limits, residual solvents, endotoxins and particle size all matter for injectable use. This guide walks through each specification item and what to confirm with the supplier.
1. Reading the Specification
| Parameter | Value (Ph. Eur. 12) | Why it matters |
|---|---|---|
| Appearance | White/almost white crystalline powder | Visual QC |
| pH | 5.0-7.5 | Solution quality for suspension |
| Assay – procaine benzylpenicillin | 96.0-102.0% | Active content |
| Assay – procaine | 39.0-42.0% | Salt stoichiometry |
| Related substances (impurities A-J) | Per monograph (each ≤0.5% max; total ≤2.0%) | Degradation/process purity |
| Water | 2.8-4.2% | Stability window |
| Residual solvents (n-butanol, ethyl acetate) | ≤5000 ppm each | Process solvent control |
| Bacterial endotoxins | ≤0.10 IU/mg | Injectable safety |
| Sterility | Complies | Aseptic-use requirement |
| Lecithin content | 0.5-1.5% | Coating specification |
| Particle size | 50% <8 μm (90% <25 μm) | Suspension behaviour |
2. What a Complete COA Should Include
- Assay results for both procaine and procaine benzylpenicillin.
- Full impurity table (each specified impurity with measured value).
- Water, residual solvents, endotoxin result.
- Sterility certificate (or reference to batch sterility test).
- Particle-size distribution and lecithin content.
3. Verification on Arrival
- Confirm appearance, assay and water first (fast checks).
- Review impurity profile against Ph. Eur. limits.
- Confirm endotoxin and sterility certificates match the batch.
4. Packaging and Storage
- Sterile API is supplied in sealed containers designed for aseptic transfer (e.g. 5-25 kg), often with desiccant.
- Store sealed, cool and dry, protected from light; reseal immediately after sampling.
5. Supplier Checklist
- Do they hold CEP / DMF and manufacturing authorization for sterile APIs?
- Can they supply particle-size and lecithin-coating tailored to your suspension?
- Do they provide change control and batch traceability?
6. FAQ
Is the lecithin-coated grade different from standard procaine penicillin?
Yes – the micronized lecithin-coated sterile grade is optimised for long-acting injectable suspensions; standard (non-coated) grades suit other routes/uses.
Can I get smaller lot sizes for qualification?
Qualification quantities are available; contact us for details.
7. References and Further Reading
- Ph. Eur. 12th Edition monograph, Procaine benzylpenicillin.
- Supplier COA, sterility certificate and MSDS for the specific grade.
This article is published for industrial and technical reference by PolyblueChem. Verify against the supplier’s COA and the applicable pharmacopoeia.
See our procaine benzylpenicillin guide and the veterinary applications guide. PolyblueChem supplies procaine benzylpenicillin (CAS 54-35-3) – contact us for specifications and quotations.