STREAMLINED METHOD DEVELOPMENT FOR ACTIVE PHARMACEUTICAL INGREDIENTS IN COLD AND FLU MEDICATION USING A SYSTEMATIC PROTOCOL

Significance of the topic

The rapid and reliable analysis of multiple active pharmaceutical ingredients (APIs) in over-the-counter cold and flu formulations is critical for quality control, regulatory compliance and batch release in the pharmaceutical industry. Streamlined UPLC methods that are compatible with mass spectrometry enable faster method development, higher throughput and improved confidence in compound identification and purity assessment.

Study overview and objectives

This work aimed to develop a systematic, MS-compatible UPLC protocol for eight common cold and flu APIs—acetaminophen, dextromethorphan HBr, phenylephrine HCl, chlorpheniramine maleate, ibuprofen, pseudoephedrine HCl, guaifenesin and doxylamine succinate—found in multi-component formulations. Key objectives were to minimize development time, achieve baseline separation within a short runtime, ensure spectral homogeneity and meet USP system suitability criteria.

Methodology and instrumentation

A three-stage systematic protocol was applied:

• Scouting: Low- and high-pH mobile phases screened for initial retention behavior.
• Screening: Two columns (ACQUITY UPLC CSH C18 and BEH C18) and solvents (methanol vs. acetonitrile) were evaluated using Empower 3 scoring reports.
• Optimization: Gradient slope, column temperature, pH and buffer composition were fine-tuned to improve resolution and peak symmetry.

Used instrumentation:

• ACQUITY UPLC H-Class PLUS system with PDA and QDa mass detectors
• ACQUITY UPLC BEH C18 column (2.1 × 50 mm, 1.7 μm)
• Mobile phase A: 10 mM ammonium acetate in water with 0.2 % ammonium hydroxide
• Mobile phase B: Methanol with 0.2 % ammonium hydroxide

Main results and discussion

The BEH C18 column with methanol produced the highest number of USP-resolution-compliant peaks in the screening step. Final conditions (0.6 mL/min, 40 °C column, gradient from 5 % to 90 % B over 5 min) separated all eight APIs in under 7.5 min. Addition of ammonium acetate buffer at pH 10 reduced tailing and improved symmetry. System suitability tests (five replicates) met USP <621> criteria for repeatability and tailing. Peak purity analysis by PDA and QDa confirmed spectral homogeneity for critical analytes such as phenylephrine.

Analysis of commercial OTC samples (Mucinex Cold, Vicks NyQuil Severe, CVS Sinus PE + Allergy, Tylenol Cold & Flu Severe) at therapeutic concentration levels demonstrated accurate, interference-free quantification of each API.

Benefits and practical applications

• Significant reduction in method development time via automated scouting and scoring.
• Robust, reproducible separation of diverse APIs in complex matrices.
• MS detection enables unambiguous peak identification and purity confirmation.
• Method readily adaptable for routine QC of multi-component cough, cold and flu products.

Future trends and opportunities

Ongoing advances in sample automation, artificial intelligence-driven method optimization and next-generation stationary phases will further accelerate multi-analyte separations. Integration of green solvents and high-throughput microflow systems may reduce solvent consumption and enhance sustainability in pharmaceutical analysis.

Conclusion

A systematic UPLC method development strategy yielded a fast, robust and MS-compatible assay for eight APIs in common cold and flu medications. The approach meets regulatory requirements, ensures spectral purity and can streamline routine quality control workflows.

References

1. Maziarz M, Rainville P. Robust and Rapid Method for Analysis of Active Pharmaceutical Ingredients in Multi-Component Cold and Flu Medication. Waters Application Note 720006523EN; 2019.
2. Maziarz M, McCarthy SM, Wrona M. Improving Effectiveness in Method Development by Using a Systematic Screening Protocol for a USP Method. Waters Application Note 720005026EN; 2014.
3. USP General Chapter <621>, Chromatography, USP45-NF36. United States Pharmacopeia Convention; 2017.