USP method transfer on UHPLC is no more challenge for the analysis of Amoxicillin Oral Suspension

Significance of the Topic

The analysis of amoxicillin oral suspension by pharmacopoeial methods ensures the quality, safety and efficacy of a widely used antibiotic in clinical and industrial settings. Transitioning from conventional HPLC to UHPLC accelerates throughput, reduces solvent consumption and aligns with green analytical chemistry initiatives without compromising regulatory compliance.

Objectives and Overview of the Study

This work aimed to transfer the USP monograph HPLC method for amoxicillin oral suspension (USP41-NF36) to an optimized UHPLC protocol using Shimadzu instrumentation. Key goals included:

• Preserving pharmacopoeial system suitability criteria (%RSD, tailing factor).
• Significantly reducing analysis time and solvent/sample use.
• Demonstrating seamless method transfer using vendor software tools.

Methodology and Instrumentation

Sample and standard solutions were prepared according to USP guidelines: a 6.8 g/L phosphate buffer at pH 5.0 ± 0.01, amoxicillin standard at 1.2 mg/mL and test solutions at 1 mg/mL. The USP HPLC method (Shim Pack GIST AQ C18, 4.6 × 250 mm, 5 µm, isocratic acetonitrile/buffer 1:24, 1.5 mL/min, 230 nm, 20 min) was converted to a UHPLC method (Shim Pack GISS C18, 2.1 × 100 mm, 1.9 µm, same mobile phase ratio, 0.4 mL/min, 0.8 µL injection, 3 min) using the Shimadzu Method Transfer Program. System suitability tests (%RSD ≤ 2.0%, tailing ≤ 2.5) were conducted for five replicates of standard and suspension.

Used Instrumentation

• Nexera UHPLC with 130 MPa high-pressure capability.
• LC-2030C Prominence-i HPLC system.
• Shim Pack GIST AQ C18 column (4.6 × 250 mm, 5 µm).
• Shim Pack GISS C18 UHPLC column (2.1 × 100 mm, 1.9 µm).
• UV detector set at 230 nm.

Main Results and Discussion

Chromatographic performance was maintained after transfer: retention times shifted from ~5.25 min to ~1.02 min with comparable peak symmetry (tailing factor ~1.29) and precision (%RSD ~0.20%). The UHPLC method reduced run time by 85% and solvent/sample usage by 96%. Chromatograms showed clear resolution of amoxicillin peaks in both standard and suspension matrices.

Benefits and Practical Applications of the Method

• High throughput: 3 min cycle time enhances sample capacity.
• Resource efficiency: significant reductions in solvent and sample consumption.
• Regulatory compliance: meets USP system suitability criteria without modification.
• Environmental impact: aligns with green analytical practices.
• Operational flexibility: vendor software simplifies method transfer.

Future Trends and Possibilities for Use

Continued adoption of UHPLC and sub-2 µm column technologies will expand to other pharmacopeial assays and complex matrices. Integration with automated sample preparation and data analytics will further streamline quality control workflows. Ultra-high-pressure systems and novel stationary phases promise even faster, more selective analyses.

Conclusion

The USP HPLC method for amoxicillin oral suspension was successfully transitioned to UHPLC using Shimadzu’s method transfer tools. The new protocol delivers equivalent chromatographic integrity with major gains in speed, efficiency and sustainability, supporting enhanced laboratory productivity and compliance.

Reference

1. Shimadzu LC World Talk International edition spring, C190-E097, 2006.
2. Dhanusha Thambavita et al., Journal of Pharmaceutical Sciences, Vol. 106, 2017.
3. USP Monograph. Amoxicillin for Oral Suspension, USP41-NF36 [p280], 2017.