Related Substances Analysis in Pharmaceuticals: A Complete FDA-Compliant Guide

Introduction: Why Related Substances Analysis Is Critical

When making medicines, it’s important to make sure that no unwanted chemicals (called “related substances”) are left behind in the final drug product. These related substances could be leftover reactants, by-products, or degradation products. That’s why Related Substances Analysis in United States is a key part of meeting FDA rules for safety and quality.

At ResolveMass Laboratories Inc., we help pharma companies detect and measure these substances accurately using advanced tools like HPLC, LC-MS, and NMR. We offer full testing support to meet the strict standards set by FDA and ICH Q3A/B.

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🔬 Explore Our Related Substance Testing Services

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What Are Related Substances?

These are any unwanted chemicals in a drug substance or product. They might come from:

• Impurities from raw materials
• Leftover reagents
• Process by-products
• Breakdown products (degradation)

Even in tiny amounts, some related substances can affect the drug’s safety. That’s why regulatory agencies require companies to identify, measure, and control them.

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Why Related Substances Analysis Matters for FDA and Health Canada

The FDA and Health Canada both want to see that your product is pure, safe, and stable over time. Related substances analysis is required during:

• IND, NDA, and ANDA filings
• Drug master file (DMF) submissions
• Stability studies

At ResolveMass, we offer Related Substances Analysis in United States and Canada using validated, compliant methods.

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Step-by-Step Guide to Related Substances Testing

Step 1: Sample Preparation

We begin with a clean, careful sample prep to avoid contamination. This includes dissolving the sample in a suitable solvent, filtration, and dilution if needed.

Step 2: Analytical Method Selection

Depending on the nature of the compound, we use:

• HPLC for general impurity profiling
• LC-MS/MS for low-level and unknown impurities
• GC for volatile impurities
• NMR for structural confirmation (Explore NMR Services)

Step 3: Method Development and Optimization

We fine-tune the method using:

• Column type
• Mobile phase
• Flow rate
• Detector settings

Step 4: Method Validation

Validation is done as per ICH Q2(R1) guidelines and covers:

• Specificity
• Linearity
• Precision
• Accuracy
• Detection limits (LOD/LOQ)

Step 5: Reporting and Documentation

We provide:

• Complete impurity profile
• Structure confirmation (if needed)
• Validation reports
• Regulatory-ready documentation for submission

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Real Case Study: FDA-Compliant Related Substances Analysis for an Antibiotic

Client: US-based generic drug manufacturer

Objective: Perform related substances testing for ANDA submission of a generic cephalosporin

Testing Tools:

• HPLC with UV detection
• LC-MS/MS for unknown impurity identification
• NMR for structure confirmation

Outcome:

• Identified and quantified 7 related substances
• One new impurity structurally confirmed via 1H-NMR and MS
• Accepted by FDA with no data deficiencies

This project shows our strength in impurity testing with clear, validated results.

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How ResolveMass Helps You Stay Compliant

ResolveMass Laboratories offers complete analytical packages:

• Impurity method development
• Validation as per ICH/FDA
• Stability studies
• Batch-to-batch comparison

We support pharmaceutical developers in Montreal, across the US, and globally with:

• GMP-certified lab
• Fast turnaround (2–4 weeks)
• Regulatory guidance from start to submission

📍 We specialize in Related Substances Analysis in United States and across Canada.

Conclusion

Related substances analysis is essential for regulatory success. It proves your drug is pure, stable, and safe for patients. At ResolveMass Laboratories, we provide FDA-compliant, ICH-aligned services for impurity profiling using world-class instruments. Whether you’re based in Canada or looking for Related Substances Analysis in United States, we’re here to support your submission from early development to final filing.

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