Analysis of antihistaminic drug under acidic condition

Importance of the Topic

The accurate and reliable separation of antihistaminic drugs is critical for pharmaceutical quality control, ensuring safety, efficacy and regulatory compliance. Basic compounds like antihistamines often interact with silica-based stationary phases, leading to poor peak shape and reproducibility. Employing optimized acidic conditions and modern column technologies addresses these challenges and enhances analytical performance.

Objectives and Study Overview

This study evaluates the capability of the Shim-pack NovaCore C18-HB column to resolve a series of seven common antihistamines under acidic mobile phase conditions. The primary goals are to achieve baseline separation within a short analysis time and to demonstrate method robustness for routine QC applications.

Methodology and Instrumentation

The separation was performed using reversed-phase liquid chromatography with a gradient of aqueous and organic mobile phases, both containing 0.1% formic acid. Key chromatographic parameters include:

• Column: Shim-pack NovaCore C18-HB, 150 mm × 4.6 mm I.D., 5 µm
• Mobile phase A: 0.1% formic acid in water
• Mobile phase B: 0.1% formic acid in acetonitrile
• Gradient program: 5% B at 0 min to 40% B at 15 min, hold to 20 min, then return
• Flow rate: 1.5 mL/min
• Injection volume: 1 µL
• Column temperature: ambient
• Detection wavelength: 254 nm

Key Results and Discussion

The chromatogram demonstrates complete separation of the seven analytes—tripelennamine, pyrilamine, chlorpheniramine, brompheniramine, chloropyramine, diphenhydramine and loratadine—within 15 minutes. Sharp, symmetric peaks with minimal tailing indicate effective suppression of silanol interactions by the acidic mobile phase. Retention times showed excellent repeatability, confirming method stability under routine conditions.

Advantages and Practical Applications

• High throughput: complete analysis in under 20 minutes
• Robust peak shapes for basic antihistamines
• Sufficient resolution for impurity or degradant profiling
• Simple isocratic-to-gradient transition for method flexibility

Future Trends and Opportunities

Future developments may include coupling this method with mass spectrometric detection to enhance sensitivity and selectivity for trace-level impurities or metabolites. Advances in core-shell and sub-2 µm particle columns could further reduce analysis times. Additionally, automated sample preparation and online monitoring are potential extensions for high-throughput pharmaceutical environments.

Conclusion

The Shim-pack NovaCore C18-HB column under acidic conditions offers a rapid, reliable and reproducible solution for the separation of antihistaminic drugs. Its performance supports routine QC and research applications, ensuring regulatory compliance and high analytical confidence.