N-Nitroso Desmethyl Eravacycline: Structure, Impurity Profiling, and Analytical Considerations

Pharmaceutical impurity control is an essential part of drug development, analytical research, and quality assurance. Even when an active pharmaceutical ingredient (API) meets its primary quality specifications, the presence of an impurity at a low concentration may require additional investigation, particularly when the impurity belongs to a class that receives specific regulatory attention.

One such class is nitrosamine drug substance-related impurities (NDSRIs). These compounds are structurally associated with an API and may require targeted evaluation because of their potential mutagenic and carcinogenic properties. Pharmaceutical manufacturers must understand their possible formation, develop appropriate analytical strategies, and assess whether detected levels meet applicable regulatory expectations.

N-Nitroso Desmethyl Eravacycline is an eravacycline-related nitrosamine impurity relevant to this area of pharmaceutical research. Understanding its chemical identity, relationship to the parent drug, and analytical requirements can help pharmaceutical quality teams plan impurity investigations and select suitable reference materials.

For procurement professionals, the challenge extends beyond finding a product by name. They must also consider chemical identity, documentation, intended analytical use, and whether the supplied material meets the requirements of their laboratory.

This article explains these considerations and how pharmaceutical impurity reference standards can support analytical work.

1. Understanding Eravacycline and Its Related Impurity

Eravacycline is a fluorocycline antibiotic belonging to the tetracycline class. It was developed to address certain bacterial infections, including complicated intra-abdominal infections. Its antibacterial activity involves inhibition of bacterial protein synthesis through interaction with the 30S ribosomal subunit.

Like other complex pharmaceutical molecules, eravacycline can be evaluated for related substances that may arise from chemical transformation, manufacturing-related processes, degradation, or other potential sources. The relevance of a particular impurity depends on its chemical identity and the circumstances under which it may occur.

N-Nitroso Desmethyl Eravacycline is identified as an eravacycline-related nitrosamine on Chemicea's product page. Its name indicates a relationship to a desmethyl form of the parent compound with an N-nitroso functional group.

This distinction matters because an API-related nitrosamine is not necessarily equivalent to a small-molecule nitrosamine that can occur across unrelated pharmaceutical products. The molecular framework of an NDSRI is connected to the parent drug, which makes compound-specific identification and evaluation important.

The presence of a listed impurity does not, by itself, establish that it occurs in a marketed eravacycline product or that a particular batch is contaminated. Actual occurrence must be assessed using appropriate evidence and analytical testing

2. Chemical Structure and Identification

Chemical structure provides the foundation for understanding an impurity and distinguishing it from the parent API and other related substances.

N-Nitroso Desmethyl Eravacycline retains substantial structural features associated with eravacycline while differing in its nitrogen-containing functional group. These differences influence how analysts approach identification, chromatographic separation, mass-spectrometric characterization, and reference-standard selection.

According to Chemicea's product listing, the compound has the following identifiers.

Chemical detail	Listed information
Product name	N-Nitroso Desmethyl Eravacycline
Catalogue number	CP-E49001
CAS number	Not available (NA)
Molecular formula	C₂₇H₃₁FN₅O₉
Molecular weight	573.53 g/mol
Availability	Custom synthesis

These details can help procurement and analytical teams identify the requested material. However, catalogue information should be checked against the supplier's current documentation before it is used in a regulated analytical procedure.

Why structural information matters

Structural information can support several laboratory activities:

- Identity confirmation: Establishing whether a candidate material is consistent with the intended chemical structure.

- Analytical method development: Evaluating appropriate detection and separation approaches for the impurity.

- Reference-standard selection: Distinguishing the target impurity from eravacycline and other structurally related compounds.

- Documentation review: Comparing molecular identifiers across supplier records, analytical procedures, and quality documentation.

A molecular formula or molecular weight alone cannot conclusively establish compound identity. These details should be considered alongside suitable analytical evidence, such as mass-spectrometric data, chromatographic behaviour, and other characterization information appropriate to the material.

For procurement teams, confirming the exact chemical name and catalogue number is particularly important when several impurities associated with the same API are being sourced.

3. Understanding Nitrosamine Impurity Formation

Nitrosamine impurities can form through different chemical pathways. One recognised pathway involves nitrosating species reacting with susceptible nitrogen-containing functional groups. Depending on the API's structure, raw materials, process conditions, and formulation environment, the potential for nitrosamine formation can vary.

For an API-related nitrosamine such as N-Nitroso Desmethyl Eravacycline, a meaningful investigation should begin with the molecular structure and a review of the relevant manufacturing and formulation processes.

Potential areas for investigation include:

Starting materials and intermediates: Raw materials, intermediates, and reagents may introduce substances that contribute to impurity formation under particular reaction conditions.

Nitrosating agents: The presence of nitrite or other relevant nitrosating species may be important where compatible chemical conditions exist.

Manufacturing conditions: Reaction conditions, processing steps, purification, and the control of residual materials may affect the potential for impurity formation.

Formulation and storage: Excipients, residual nitrites, environmental conditions, and packaging-related factors can be relevant to nitrosamine risk assessments for certain drug products.

These are general investigation areas, not confirmation of a specific formation mechanism for N-Nitroso Desmethyl Eravacycline. A compound-specific pathway should be established through appropriate chemical evidence rather than inferred solely from the impurity's name.

For pharmaceutical manufacturers, the practical objective is to identify credible risks, evaluate the evidence, and implement controls proportionate to the potential impact on product quality.

4. Why Impurity Profiling Is Important

Impurity profiling involves identifying, characterising, and, where required, quantifying impurities associated with an API or finished pharmaceutical product. It helps manufacturers understand the composition of a sample and determine whether observed impurities require further investigation.

Nitrosamine-related impurities deserve particular attention because their evaluation may involve additional considerations beyond conventional related-substances testing.

For N-Nitroso Desmethyl Eravacycline, an impurity profiling programme may address the following questions:

• Is the target impurity present in the sample?

• Can it be distinguished from eravacycline and other related compounds?

• Is the analytical method sufficiently sensitive for the intended purpose?

• Can the impurity be quantified reliably at the relevant concentration?

• Are the results suitable for the applicable quality or regulatory assessment?

Answering these questions requires an analytical approach suited to the compound, the sample matrix, and the purpose of testing.

Qualitative and quantitative assessment

Qualitative analysis focuses on determining whether the target compound is present and whether the analytical evidence supports its identity. Quantitative analysis measures the amount present using an appropriately developed and validated or otherwise qualified method, as applicable.

These activities are related but not interchangeable. A signal that is consistent with a suspected impurity may require further confirmation, while a quantitative result depends on factors such as calibration, selectivity, precision, and the suitability of the reference material.

A robust impurity profile should therefore rely on a clearly defined analytical objective rather than treating detection alone as proof of complete characterisation.

5. Analytical Considerations for N-Nitroso Desmethyl Eravacycline

The selection of an analytical method depends on the chemical properties of the impurity, the expected concentration, the sample matrix, and the required reporting limit.

For pharmaceutical nitrosamine investigations, liquid chromatography coupled with mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS/MS) may be considered where appropriate. Such techniques can combine chromatographic separation with mass-based detection, supporting the investigation of target compounds at low concentrations.

However, the suitability of a particular method for N-Nitroso Desmethyl Eravacycline must be demonstrated. A method developed for another nitrosamine or another tetracycline-related compound should not automatically be assumed to provide equivalent performance.

Chromatographic separation

Chromatography helps separate the target impurity from the parent API, related substances, excipients, and other sample components. The separation must be sufficient for the intended analytical purpose, especially when compounds have similar structural features.

Method developers may need to evaluate column chemistry, mobile-phase composition, gradient conditions, sample preparation, and potential matrix interference.

Mass-spectrometric identification

Mass spectrometry can provide information about the molecular mass and fragmentation behaviour of a compound. When combined with chromatographic retention and other relevant evidence, these data can help support identification.

A single mass signal is not always conclusive because unrelated compounds may produce overlapping signals or similar fragments. Appropriate confirmation criteria should be established for the method.

Sensitivity and quantification

Nitrosamine investigations may require measurement at very low concentrations. The laboratory should establish that the method's sensitivity is suitable for its intended use and relevant decision limits.

Important performance characteristics can include:

• Selectivity and specificity for the target impurity.

• Limit of detection and limit of quantification, where applicable.

• Accuracy and precision.

• Linearity and calibration performance.

• Recovery during sample preparation.

• Stability of prepared samples and reference solutions.

• Potential interference from the API or sample matrix.

These characteristics should be evaluated according to the analytical procedure, applicable guidance, and the intended use of the results.

Avoiding false conclusions

The absence of a detectable signal does not automatically establish that an impurity is absent. The conclusion depends on the method's sensitivity, selectivity, sampling strategy, and the conditions under which the analysis was performed.

Similarly, a positive signal should be evaluated against suitable identification criteria before the result is treated as confirmed.

The FDA provides guidance on nitrosamine control and recommends analytical approaches for confirmatory testing of certain nitrosamine impurities. Laboratories should consult the current guidance and determine which recommendations apply to their particular compound and use case.

6. The Role of Reference Standards in Impurity Testing

A reference standard provides a defined material against which an analytical measurement or identification can be evaluated. In impurity analysis, selecting an appropriate reference material is especially important when the target compound is structurally related to the API.

For N-Nitroso Desmethyl Eravacycline, an appropriate reference material may support method development, identity assessment, calibration, and other laboratory activities, depending on its documented suitability.

The exact role of the material should be established before it is incorporated into an analytical procedure.

What procurement teams should verify

Before purchasing a specialised impurity reference standard, procurement professionals should review several points.

1. Chemical identity

Confirm the compound name, catalogue number, molecular formula, molecular weight, and CAS number where available. If an identifier is unavailable, ask the supplier what supporting identification documents can be provided.

2. Documentation availability

Ask about the certificate of analysis (CoA), available characterization data, assigned purity or assay, and other relevant technical documents. Confirm that the documents match the specific material being supplied.

3. Intended application

Clarify whether the material is required for research, method development, impurity identification, quantitative analysis, or another purpose. Requirements can differ between applications.

4. Purity and assigned values

Understand how purity or assay values are determined and whether any assigned value is appropriate for the intended calculations. Do not assume that every reference material has the same certification status or metrological traceability.

5. Supply and handling

Confirm pack size, availability, lead time, storage conditions, shipping arrangements, and any special handling requirements before placing an order.

6. Technical communication

For compounds available through custom synthesis, ask the supplier to clarify the proposed scope, expected documentation, and any limitations affecting the requested application.

A careful review of these points can help laboratories reduce procurement errors and select materials that fit their analytical requirements.

7. Regulatory Context and Acceptable Intake Considerations

Regulatory assessment is an important part of nitrosamine impurity management. Authorities have developed approaches for evaluating nitrosamine-related risks, including NDSRIs that share structural features with an API.

The US Food and Drug Administration (FDA) publishes recommended acceptable intake limits for certain nitrosamine impurities. In its current published table, N-nitroso-desmethyl-eravacycline is listed with a recommended acceptable intake of 400 ng/day and a predicted carcinogenic potency category of 3.

This figure provides useful regulatory context for pharmaceutical quality teams. It should nevertheless be interpreted carefully.

An acceptable intake (AI) is a daily intake value used in a safety assessment. It is not the same as a measured impurity concentration in a drug product, a reference-standard purity specification, or an analytical method's detection limit.

The applicable assessment may depend on the relevant regulatory authority, the current guidance, the intended patient population, the product's maximum daily dose, and any compound-specific information or updated recommendations.

Manufacturers should therefore:

• Check the latest applicable regulatory guidance before establishing acceptance criteria.

• Review whether compound-specific recommendations supersede general assessment approaches.

• Evaluate actual analytical results against the appropriate criteria.

• Document the scientific rationale for the selected control strategy.

• Reassess the strategy when new information becomes available.

The FDA's published recommendations are not automatically universal requirements in every jurisdiction. Companies marketing products in multiple countries should assess the relevant regional requirements and consult qualified regulatory professionals when necessary.

8. How Chemicea Supports Pharmaceutical Impurity Research

Pharmaceutical laboratories often need specialised impurity materials that may not be available as routine catalogue items. Supplier selection can therefore involve more than checking a product name and price; it may require technical discussions about chemical identity, documentation, intended use, and supply feasibility.

Chemicea Pharmaceuticals Pvt. Ltd. supplies pharmaceutical impurity reference standards and offers custom synthesis capabilities for specialised compounds. Its product catalogue includes nitrosamine-related impurities and other pharmaceutical reference materials.

For organisations investigating eravacycline-related impurities, Chemicea lists N-Nitroso Desmethyl Eravacycline under catalogue number CP-E49001, with availability indicated as custom synthesis. The listed CAS number is NA, so buyers should confirm the identification and documentation available for their specific requirements.

When contacting the supplier, procurement teams should specify their intended application, required quantity, documentation expectations, and any relevant analytical requirements. This helps establish whether the offered material is suitable for the intended laboratory work.

The goal is to obtain a material that meets the project's technical requirements rather than selecting a product based on its name alone.

Frequently Asked Questions

What is N-Nitroso Desmethyl Eravacycline?

N-Nitroso Desmethyl Eravacycline is an eravacycline-related nitrosamine impurity listed by Chemicea as a pharmaceutical impurity reference material available through custom synthesis. Its potential relevance is evaluated through compound identification, impurity testing, and applicable nitrosamine risk-assessment procedures.

What is the molecular formula of N-Nitroso Desmethyl Eravacycline?

Chemicea lists its molecular formula as C₂₇H₃₁FN₅O₉ and molecular weight as 573.53 g/mol. The product page lists the CAS number as unavailable (NA). Buyers should verify the current technical documentation before using these details in regulated work.

Why are reference standards important for nitrosamine analysis?

Suitable reference standards can support compound identification, analytical method development, calibration, and quantitative assessment. Their usefulness depends on the quality of the supporting documentation and their suitability for the intended procedure.

Which analytical techniques may be considered?

LC-MS and LC-MS/MS may be appropriate for certain nitrosamine investigations, depending on the compound, sample matrix, and required sensitivity. The method must be evaluated for selectivity, sensitivity, accuracy, precision, and other relevant performance characteristics before it is relied upon.

What acceptable intake does the FDA list for this impurity?

The FDA's published table lists a recommended acceptable intake of 400 ng/day for N-nitroso-desmethyl-eravacycline, under predicted carcinogenic potency category 3. This recommendation should be checked against the latest applicable FDA guidance and any relevant regional requirements.

How can I enquire about N-Nitroso Desmethyl Eravacycline from Chemicea?

Visit the Chemicea product page to review the listing and submit an enquiry. Include your required quantity, intended analytical application, and documentation requirements so the supplier can assess your request.

Conclusion

N-Nitroso Desmethyl Eravacycline is a specialised eravacycline-related nitrosamine impurity whose evaluation requires attention to chemical identity, analytical performance, and the relevant regulatory framework. For pharmaceutical manufacturers and procurement teams, the priority is to ensure that the selected reference material and analytical procedure are suitable for the intended purpose.

Understanding the difference between impurity identification, quantitative analysis, and regulatory risk assessment helps laboratories make better-informed decisions. Equally important is verifying supplier documentation, confirming material suitability, and checking current regulatory recommendations rather than relying on general assumptions.

Chemicea's listing for N-Nitroso Desmethyl Eravacycline provides a starting point for laboratories seeking this specialised material through a custom-synthesis enquiry. By clearly communicating technical requirements and reviewing the available supporting documentation, buyers can make a more informed decision for their pharmaceutical impurity research and quality-control activities.