Atosiban Acetate API (CAS 90779-69-4) Manufacturer | QA Guide on Peptide Synthesis
Atosiban Acetate API, CAS 90779-69-4, synthetic cyclic peptide, peptide macrocyclization, SPPS peptide manufacturer, tocolytic raw material, oxytocin receptor antagonist, peptide dimer impurity, TFA-to-acetate conversion
Content
⚠️ B2B Compliance & Identity Notice
Shaanxi Sunrise (Pharma-Sunrise) operates strictly as an upstream B2B chemical manufacturer and advanced peptide synthesis facility. The materials discussed herein, including Atosiban Acetate API Powder (CAS 90779-69-4), are raw pharmaceutical ingredients designed exclusively for qualified R&D laboratories, CDMOs, and industrial formulation engineers. Not for direct human consumption. No C-end retail inquiries will be entertained.
Obstetrics Leaves No Room for Chemical Ambiguity
When a CDMO formulates a tocolytic agent, they are not developing a casual topical cream. They are engineering a critical, life-saving intravenous (IV) infusion designed to halt premature labor. In this clinical arena, the API must be flawless. Atosiban Acetate (CAS 90779-69-4)—a highly potent, synthetic cyclic nonapeptide acting as a competitive antagonist of oxytocin receptors—is the gold standard. But step away from the clinical data and onto the heavy industrial synthesis floor, and the reality hits immediately: manufacturing this nine-amino-acid ring is a thermodynamic nightmare.
The Cyclic Minefield: Why Generic SPPS Architectures Fail
1. Macrocyclization vs. Intermolecular Dimerization
The functional integrity of Atosiban relies entirely on closing the ring by forming a disulfide bridge between Mpa at position 1 and Cys at position 6. If the concentration of the linear peptide in the reaction vessel is marginally too high, molecules collide, creating intermolecular bonds (dimers) instead of intramolecular rings. The resulting dimers possess unpredictable receptor-binding affinities.
2. The β-Branched Blockade: Ile³ and Thr⁴
Positions 3 and 4 utilize Isoleucine and Threonine—both β-branched amino acids. When attempting to couple two consecutive β-branched residues on a solid resin, they create a massive steric wall. Substandard synthesis protocols relying on weak coupling reagents often stall here, resulting in deletion sequences that are nearly impossible to separate downstream.
3. The Asparagine (Asn) Dehydration Time-Bomb
During SPPS, if the amide side chain of Asn (Position 5) is exposed to strong activating reagents, it rapidly undergoes dehydration, converting into a highly toxic cyano (nitrile) group. Generic manufacturers often ship batches that look pure on crude UV-HPLC scans but fail mass spectrometry due to this cyano-impurity.
Auditor's Metric: Generic Market vs. Sunrise Parameters
| Analytical Parameter | Generic Market Standard | Sunrise Internal Standard |
|---|---|---|
| HPLC Purity (Area %) | ≥ 98.0% | ≥ 99.50% (Strictly Enforced) |
| Single Maximum Impurity | ≤ 1.0% | ≤ 0.10% (Identified via HRMS) |
| TFA Limit | > 5.0% | ≤ 0.5% (Strict Acetate Form) |
Formulation & QA Auditor FAQ
Q1: How do you mathematically guarantee the absence of intermolecular dimers?
Every single batch of Sunrise Atosiban Acetate API undergoes comprehensive High-Resolution Mass Spectrometry (HRMS) combined with Size-Exclusion Chromatography (SEC). We confirm the exact monoisotopic mass (993.4 Da). If mass spectra detect any signal at ≈1986 Da (the dimer), the batch fails release. We guarantee dimer limits well below 0.1%.
Q2: What is the exact endotoxin limit for your Atosiban powder?
Because Atosiban is primarily formulated for intravenous (IV) injection in critical care obstetrics, bioburden control is paramount. We enforce strict cleanroom protocols, utilize depyrogenated glassware, and execute terminal sterile filtration (0.22 μm). Endotoxin levels are routinely tested via the kinetic chromogenic LAL assay, strictly enforced to < 1 EU/mg.
Q3: How do you verify that the D-Tyr(Et) residue hasn't racemized?
We utilize specialized chiral stationary phases during our in-process analytical checks. By applying highly tailored mobile phase gradients and utilizing optimized coupling reagents (e.g., DIC/Oxyma), we kinetically suppress the racemization pathway from the start.
Do Not Compromise Your IV Pipeline with Substandard Peptides.
Shaanxi Sunrise provides verifiable, high-throughput Atosiban Acetate API engineered for rigorous global CDMOs. Demand the analytical data. We have it ready.
REQUEST FULL COA, LC-MS DATA & B2B QUOTE TODAY*Strictly for B2B procurement, qualified researchers, and industrial compounding entities.