Analysis of Nimodipine AP

Analysis of Nimodipine API Using Shim-pack GIST C18-AQ Column

Importance of the Topic

Nimodipine is a calcium channel blocker widely used to prevent cerebral vasospasm. Reliable quantification and impurity profiling of this active pharmaceutical ingredient (API) are essential to ensure product safety and therapeutic efficacy.

Study Objectives and Overview

The primary goal was to develop and validate a straightforward reverse-phase liquid chromatography method capable of separating and quantifying nimodipine and its related impurities under isocratic conditions using Shimadzu Shim-pack GIST C18-AQ stationary phase.

Methodology and Instrumentation

• Column: Shim-pack GIST C18-AQ (250 mm × 4.6 mm I.D., 5 μm particle size).
• Mobile phase (isocratic): Methanol : Acetonitrile : Water in a ratio of 35 : 38 : 27.
• Flow rate: 1.0 mL/min; Column temperature: 40 °C; Injection volume: 20 μL.
• Sample vials: LabTotal™ Vial for LC/LCMS.
• Detection: UV absorbance at 235 nm.

Main Results and Discussion

The optimized method achieved clear baseline separation of nimodipine and two impurities (Impurity I and Impurity C). Standard mixtures containing 0.2 mg/mL of impurity I and API, and 1.0 μg/mL of impurity C yielded well-defined peaks, demonstrating the method’s sensitivity and resolution for routine quality control analyses.

Benefits and Practical Applications

• High reproducibility and specificity for impurity profiling.
• Isocratic elution simplifies system setup and reduces run-to-run variability.
• Suitable for quality assurance, regulatory compliance, and batch release testing in pharmaceutical development.

Future Trends and Potential Applications

Future work may integrate mass spectrometric detection for in-depth impurity identification and adopt ultrahigh-performance liquid chromatography (UHPLC) formats to decrease analysis time and solvent usage, enhancing throughput and sustainability.

Conclusion

The described LC method employing Shim-pack GIST C18-AQ provides a robust, reproducible approach for nimodipine determination and impurity assessment, supporting stringent quality control frameworks in pharmaceutical manufacturing.