Analysis of Omeprazole by "i-Series" for USP and JP Methods

Importance of the Topic

Omeprazole is a proton pump inhibitor widely prescribed for gastric and duodenal ulcers and reflux esophagitis. Precise quantification of omeprazole by chromatography is critical for ensuring pharmaceutical quality and patient safety.

Objectives and Overview of the Study

This application note demonstrates omeprazole assays following United States Pharmacopeia (USP) and Japanese Pharmacopoeia (JP) monographs, and presents a high-speed USP-compliant method achieved by column dimension and flow adjustments on Shimadzu systems.

Methodology and Instrumentation

• USP Original Method:
   Column: Shim-pack GIST C8, 150×4.6 mm, 5 µm
   Mobile Phase: Acetonitrile/Phosphate buffer (pH 7.6) 1 ∶ 3 (v/v)
   Flow Rate: 0.80 mL/min; Temperature: 40 °C; Injection Volume: 20 µL; Detection: UV 280 nm
• USP Fast Method:
   Column: Shim-pack GIST C8, 50×3.0 mm, 2 µm
   Flow Rate: 0.85 mL/min; Injection Volume: 8 µL; other parameters as original
• JP Method:
   System: Prominence-i HPLC
   Column: Shim-pack GIST C8, 150×4.6 mm, 5 µm
   Mobile Phase: Phosphate buffer (pH 7.6)/Acetonitrile 29 ∶ 11 (v/v); Flow Rate: 1.3 mL/min; Temperature: 25 °C; Injection Volume: 10 µL; Detection: UV 280 nm
• Instrumentation:
   Shimadzu Nexera-i integrated UHPLC for USP methods and Prominence-i integrated HPLC for JP methods

Main Results and Discussion

• USP Methods:
   System suitability criteria (tailing factor ≤1.5, RSD ≤1.0 %) were met in both original and fast methods.
   Fast method reduced analysis time by over 80 % while preserving resolution.
• JP Method:
   Required detectability (15–25 %) observed at 19.7 %.
   Resolution between omeprazole and 1,2-dinitrobenzene: 23.6 (>10 threshold).
   Repeatability RSD: 0.20 % (<2 %).

Benefits and Practical Application

The validated assays enable pharmaceutical QC laboratories to perform USP- and JP-compliant omeprazole quantification with enhanced throughput. Shimadzu’s Nexera-i system facilitates seamless transfer of existing HPLC protocols to UHPLC speeds without hardware modifications.

Future Trends and Possibilities

• Adoption of smaller particle columns and ultra-high-pressure systems for faster separations.
• Green chromatography initiatives to minimize solvent use and waste.
• Integration of LC-MS and other hyphenated techniques for detailed impurity profiling.
• Utilization of artificial intelligence for automated method development and optimization.

Conclusion

This work confirms that both USP and JP monograph requirements for omeprazole analysis are satisfied. The proposed fast USP method significantly increases sample throughput while maintaining analytical performance.

References

• United States Pharmacopeia General Chapter 621: Chromatography
• Japanese Pharmacopoeia, 16th Edition: Monograph for Omeprazole