Stability-Indicating RP-HPLC Method Development and Validation for Estimation of Remdesivir in Bulk and Pharmaceutical Formulations: A Comprehensive Review

Remdesivir, a nucleotide prodrug, is a key therapeutic agent against SARS-CoV-2. As the pharmaceutical industry emphasizes drug quality and stability, robust analytical methods are essential for regulatory compliance and ensuring safety. RP-HPLC is a widely adopted analytical technique for quantifying remdesivir due to its accuracy, sensitivity, and reproducibility.

This review consolidates existing research on RP-HPLC methods for remdesivir, focusing on critical aspects such as method optimization, forced degradation studies, and validation parameters. The integration of stability-indicating features enables the detection of degradation products, enhancing the reliability of remdesivir formulations.

       
           
       
Method Development

1. Chromatographic Conditions

- Mobile Phase: Various combinations of aqueous buffers (e.g., phosphate buffer, pH 3.0–5.0) and organic solvents (e.g., acetonitrile or methanol) are optimized to achieve peak resolution and symmetrical elution.

- Column: C18 columns (250 mm × 4.6 mm, 5 µm) are preferred for their compatibility with hydrophobic compounds like remdesivir.

- Flow Rate: Typically maintained at 1.0 mL/min, balancing resolution and runtime.

- Detection Wavelength: UV detection at 240–260 nm offers optimal sensitivity for remdesivir.

2. Retention Time: Sharp and well-resolved peaks ensure efficient separation of remdesivir and its degradation products within 8–12 minutes.

3. Sample Preparation: Proper dilution and filtration minimize interference and enhance the accuracy of analysis.

Forced degradation testing is a critical component of stability-indicating methods, simulating conditions that cause drug degradation. Key stress conditions include:

1. Acidic and Alkaline Hydrolysis: Degradation under strong acid (0.1 N HCl) and base (0.1 N NaOH) conditions provides insights into pH sensitivity.

2. Oxidative Stress: Exposure to 3–5% hydrogen peroxide evaluates remdesivir’s stability against reactive oxygen species.

3. Thermal Stress: Heating at 60°C for 24–48 hours assesses thermal stability.

4. Photolytic Stress: UV light exposure (254 nm) determines photostability, simulating real-world storage conditions.

Validation Parameters

Validation ensures the reliability and reproducibility of the RP-HPLC method. Key parameters validated according to ICH Q2(R1) guidelines include:

1. Specificity: Ensures separation of remdesivir from excipients and degradation products.

2. Linearity: Calibration curves exhibit linearity with R?2; > 0.999 in concentration ranges (10–100 µg/mL).

3. Accuracy: Recovery studies (98–102%) confirm method reliability.

4. Precision: Low %RSD (<2>

5. LOD and LOQ: Sensitivity is demonstrated with LOD (0.5 µg/mL) and LOQ (1.5 µg/mL).

6. Robustness: Minor variations in chromatographic conditions show consistent performance.