SIMULTANEOUS DETERMINATION OF NAPHAZOLINE HYDROCHLORIDE AND PHENIRAMINE MALEATE ALONG WITH THEIR RELATED COMPOUNDS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Importance of the Topic

Analytical protocols for ophthalmic and nasal formulations often require separate chromatographic methods for each active pharmaceutical ingredient (API), leading to increased solvent consumption, hazardous waste generation and longer turnaround times. Developing a unified high-performance liquid chromatography (HPLC) technique for simultaneous quantification of naphazoline hydrochloride and pheniramine maleate along with their related impurities addresses environmental, regulatory and efficiency challenges in pharmaceutical quality control.

Objectives and Study Overview

This work aimed to merge three United States Pharmacopeia (USP) monographs into a single HPLC method capable of:

• Identifying and quantifying naphazoline HCl and pheniramine maleate APIs.
• Separating and measuring their respective related compounds at low levels.
• Ensuring compliance with USP system suitability, precision and resolution criteria.

Methodology and Instrumentation

Sample Preparation:

• Standard stock solutions of APIs and impurities were prepared in a 90:10 mixture of mobile phase A (aqueous 0.05% triethylamine/phosphoric acid) and mobile phase B (0.05% phosphoric acid in acetonitrile).
• Resolution mixtures contained 500 µg/mL pheniramine maleate and 40 µg/mL naphazoline HCl with 5 µg/mL of each related compound.
• Commercial ophthalmic and nasal samples were diluted to match working concentrations.

Chromatographic Conditions:

• Instrumentation: Alliance iS HPLC system with tunable UV detector set at 260 and 280 nm.
• Column: XSelect CSH C18 (4.6×150 mm, 5 µm), maintained at 40 °C; sample tray at 5 °C.
• Injection volume: 8 µL; flow rate: 2.0 mL/min.
• Mobile phase gradient: hold at 5% B for 6 min, linear to 95% B over 7 min.

Main Results and Discussion

System Suitability and Precision:

• 12 replicate injections of the system suitability mixture demonstrated %RSD <0.1% for peak areas and <0.15% for retention times.
• Inter-day precision (17 injections over two days) confirmed method robustness.

Linearity:

• Calibration over 80–120% of target concentrations yielded correlation coefficients (R²) >0.997 for both APIs.

Resolution:

• All peaks, including impurities, resolved with USP resolution values ≥2.4, exceeding acceptance criteria.

Application to Commercial Samples:

• Ophthalmic and nasal formulations containing single or combined APIs were analyzed successfully without interference from excipients.

Benefits and Practical Applications

The unified HPLC method delivers:

• Reduced solvent consumption and hazardous waste production.
• Shorter analysis time by combining multiple monograph tests.
• Validated performance for routine quality control in pharmaceutical laboratories.

Future Trends and Opportunities

Potential developments include:

• Extension to other multi-component drug formulations.
• Integration with mass spectrometric detection for enhanced specificity.
• Further optimization of mobile phases toward greener solvents.
• Automation and high-throughput adaptations for large-scale QC operations.

Conclusion

A single, robust HPLC method was established and validated for simultaneous determination of naphazoline hydrochloride, pheniramine maleate and their related impurities. The approach meets USP requirements for system suitability, precision, linearity and resolution, streamlining analysis and reducing environmental impact.

References

[1] USP Monograph, Naphazoline Hydrochloride Nasal Solution, USP40-NF35, United States Pharmacopeia, December 2017.
[2] USP Monograph, Naphazoline Hydrochloride Ophthalmic Solution, USP40-NF35, United States Pharmacopeia, December 2017.
[3] USP Monograph, Naphazoline Hydrochloride and Pheniramine Maleate Ophthalmic Solution, USP40-NF35, United States Pharmacopeia.