Simultaneous Determination of Naphazoline Hydrochloride and Pheniramine Maleate along with their Related Compounds by High Performance Liquid Chromatography on an Alliance™ iS HPLC System

Importance of the topic

Simultaneous quantification of naphazoline hydrochloride and pheniramine maleate along with related impurities is crucial for ensuring the quality, safety, and efficacy of combined ophthalmic and nasal formulations. Regulatory requirements demand accurate assay and impurity profiling to meet USP monograph standards and to minimize use of hazardous solvents.

Objectives and Study Overview

The study aimed to consolidate three separate USP chromatographic methods into a single high-performance liquid chromatography (HPLC) procedure for simultaneous determination of both APIs and their specified related compounds in ophthalmic and nasal solutions.

Methodology and Instrumentation

• Chromatographic system: Waters Alliance iS HPLC coupled with a Tunable UV detector operating at 260 and 280 nm.
• Column: XSelect CSH C18, 5 um, 4.6 x 150 mm, thermostated at 40 °C.
• Mobile phases: A – 0.05% triethylamine and 0.05% phosphoric acid in water; B – 0.05% phosphoric acid in acetonitrile.
• Gradient: initial 6 min at 5% organic, then linear to 95% organic over 7 min; flow rate of 2.0 mL/min.
• Sample preparation: standards and spiked mixtures at API concentrations of 500/40 ug/mL with 5 ug/mL impurities; storage at -20 °C.
• Data handling: Empower 3 Chromatographic Data System.

Main Results and Discussion

• System suitability: 12 replicate injections showed %RSD <0.1% for peak areas and <0.15% for retention times, confirming repeatability.
• Linearity: calibration curves over 80–120% API concentration range yielded R2 >0.997 for both APIs.
• Resolution: all related compounds were baseline separated with minimum USP resolution of 2.4.
• Precision: intra-day and inter-day %RSD values remained below 0.6%, demonstrating method robustness.
• Application: method successfully quantified APIs in six commercial ophthalmic and nasal products, with assay recoveries within 90–110%.

Benefits and Practical Applications

This single-run HPLC method streamlines quality control by replacing multiple monograph procedures, reducing analysis time, solvent consumption, and hazardous waste. It ensures compliance with USP criteria while supporting routine assay and impurity testing in pharmaceutical laboratories.

Future Trends and Potential Applications

• Implementation of greener mobile phases and solvent-reduction strategies to align with environmental sustainability goals.
• Integration of hyphenated techniques, such as LC-MS, for more comprehensive impurity identification.
• Automation and high-throughput workflows to further enhance laboratory efficiency in QA/QC settings.
• Adoption of quality by design (QbD) frameworks to optimize method performance and lifecycle management.

Conclusion

A robust and efficient HPLC approach was developed for concurrent analysis of naphazoline hydrochloride, pheniramine maleate, and their impurities. Validation demonstrated excellent performance in terms of precision, accuracy, linearity, and selectivity, making the method suitable for routine pharmaceutical quality control.

References

• [1] A. Uncini et al., Acta Neurol Scand 87(4) (1993) 322–324.
• [2] L. Quan, H. He, Mol Med Rep 13(4) (2016) 3319–3325.
• [3] USP Monograph Naphazoline Hydrochloride Nasal Solution, USP40-NF35 (2017).
• [4] USP Monograph Naphazoline Hydrochloride Ophthalmic Solution, USP40-NF35 (2017).
• [5] USP Monograph Naphazoline Hydrochloride and Pheniramine Maleate Ophthalmic Solution, USP40-NF35 (2017).