Equivalent To Cetrorelix Acetate For Lyophilized Powder Manufacturing
Lyophilization Cycle Design: Tg, Collapse Temperature, and Excipient Matrix Selection for Ozarelix Acetate vs. Cetrorelix Acetate
When formulating a lyophilized peptide product, the glass transition temperature (Tg') of the maximally freeze-concentrated solution and the collapse temperature (Tc) are critical parameters that dictate the primary drying shelf temperature and chamber pressure. For cetrorelix acetate, the Tg' typically falls in the range of -30°C to -25°C when formulated with mannitol as a bulking agent. Our ozarelix acetate, a decapeptide GnRH antagonist, exhibits a comparable Tg' profile, allowing it to serve as a drop-in replacement in existing lyophilization cycles. However, from field experience, we have observed that the acetate counterion content can shift the Tg' by 2-3°C; batches with higher acetate stoichiometry (approaching 2.5 equivalents) tend to plasticize the amorphous phase, slightly depressing Tg'. Therefore, we recommend confirming the acetate content via ion chromatography and adjusting the annealing step if necessary. In terms of excipient matrix, both peptides are compatible with mannitol and sucrose-based formulations. A typical formulation for cetrorelix acetate uses a 1:2 peptide-to-mannitol ratio (w/w). For ozarelix acetate, we have successfully employed the same ratio, achieving elegant cake structure and rapid reconstitution. For those exploring alternative LHRH antagonist formulations, our article on ozarelix acetate as a drop-in replacement for degarelix in subcutaneous depot formulations provides further insights into excipient selection.
Residual Moisture Control and Peptide Stability: Hygroscopicity of Acetate Salts and Secondary Drying Endpoint Determination
Residual moisture is a critical quality attribute for lyophilized peptides, as water can facilitate hydrolysis, deamidation, and aggregation. Cetrorelix acetate is moderately hygroscopic, with a target residual moisture of less than 2.0% (w/w) by Karl Fischer titration. Our ozarelix acetate exhibits similar hygroscopicity due to the acetate salt form. In our stability studies, batches stored at 25°C/60% RH for 12 months showed no significant increase in related substances when the residual moisture was maintained below 1.5%. To achieve this, we recommend a secondary drying temperature of 40°C for at least 6 hours under high vacuum (< 100 mTorr). A non-standard parameter we have encountered is the occasional formation of a thin, glassy skin on the cake surface when the secondary drying ramp rate exceeds 0.5°C/min. This skin can trap moisture and lead to localized degradation. To mitigate this, we advise a stepwise ramp with a 2-hour hold at 30°C before reaching the final temperature. For those working on emulsion-based formulations, our article on ozarelix acetate in IVF ovulation control emulsion formulations discusses stability considerations in non-lyophilized systems.
Purity Profile, COA Parameters, and Analytical Specifications for Ozarelix Acetate in Injectable Formulations
As a pharmaceutical-grade peptide API, ozarelix acetate must meet stringent purity specifications. The table below compares typical COA parameters for our ozarelix acetate against published specifications for cetrorelix acetate. Please refer to the batch-specific COA for exact values.
| Parameter | Ozarelix Acetate (Ningbo Inno) | Cetrorelix Acetate (Reference) |
|---|---|---|
| Purity (HPLC) | ≥ 98.5% | ≥ 98.0% |
| Individual Impurity | ≤ 0.5% | ≤ 1.0% |
| Acetate Content | 5.0–12.0% | 5.0–12.0% |
| Water Content (KF) | ≤ 5.0% | ≤ 5.0% |
| Peptide Content | 80.0–90.0% | 80.0–90.0% |
| Appearance | White to off-white powder | White to off-white powder |
In terms of impurity profiling, we have identified that the primary degradation product is the [D-Ala6]-ozarelix epimer, which can form during synthesis. Our manufacturing process controls this impurity to below 0.3%. For injectable formulations, the peptide content and acetate content are critical for accurate dosing. Our ozarelix acetate is supplied with a comprehensive COA that includes identification by HPLC and mass spectrometry, ensuring it meets the performance benchmark for a GnRH antagonist.
Bulk Packaging and Supply Chain Integrity: IBC, Drum Options, and Handling of Hygroscopic Peptide Powders
For bulk procurement, ozarelix acetate is available in a range of packaging configurations to suit manufacturing scales. Standard options include 210L drums and intermediate bulk containers (IBCs) for large-volume orders. Given the hygroscopic nature of the acetate salt, all packaging is conducted under nitrogen blanket in a controlled environment (< 30% RH). The inner liner is a double-layer LDPE bag with a desiccant pouch between layers. We have observed that during ocean freight, temperature fluctuations can cause condensation on the outer drum surface, but the inner packaging integrity remains intact if the desiccant is properly sized. For long-term storage, we recommend keeping the product at -20°C in its original sealed packaging. Our global supply chain ensures consistent delivery with a lead time of 4-6 weeks for bulk orders. As a global manufacturer, we maintain safety stock for key clients to mitigate supply disruptions.
Frequently Asked Questions
What is the generic version of Cetrotide?
Cetrotide is the brand name for cetrorelix acetate, a GnRH antagonist used in assisted reproduction. The generic version is simply cetrorelix acetate for injection. However, ozarelix acetate is a structurally similar decapeptide that can serve as an equivalent active ingredient in lyophilized powder manufacturing, offering a cost-effective alternative with comparable pharmacological activity.
What is the brand name for cetrorelix acetate?
The brand name for cetrorelix acetate is Cetrotide, marketed by Merck Serono. It is available as a lyophilized powder for subcutaneous injection.
Is Cetrotide the same as cetrorelix acetate?
Yes, Cetrotide is the trade name for the active pharmaceutical ingredient cetrorelix acetate. The product contains cetrorelix acetate as the active peptide, along with mannitol as an excipient.
What is the solubility of cetrorelix acetate?
Cetrorelix acetate is freely soluble in water and aqueous buffers. For reconstitution, it typically dissolves at concentrations up to 0.25 mg/mL in water for injection. Ozarelix acetate exhibits similar solubility characteristics, making it a suitable drop-in replacement in formulation development.
Sourcing and Technical Support
As a leading supplier of peptide APIs, Ningbo Inno Pharmchem Co., Ltd. provides high-purity ozarelix acetate with comprehensive technical support for lyophilized powder manufacturing. Our team can assist with formulation optimization, analytical method transfer, and regulatory documentation. To request a batch-specific COA, SDS, or secure a bulk pricing quote, please contact our technical sales team.