Development of a robust and reliable reverse-phase high-performance liquid chromatography (RP-HPLC) method using analytical quality by design principles for the accurate determination of esculin in its bulk form

Background

Analytical quality by design is a proactive, holistic, and data-driven approach to quality that emphasizes risk assessment and management. This can lead to more robust and reliable methods than traditional approaches. Using principles of analytical quality by design for method development can help to assure the quality and consistency of analytical methods. This is important for the pharmaceutical industry, where accurate and reproducible analytical methods are essential for ensuring drug safety, shelf life, and efficacy. Esculin is a naturally occurring derivative of coumarin that is found in the stems of the plant Aesculus indica. The present study describes the use of an analytical quality by design approach to develop and validate a reliable RP-HPLC method for the analysis of esculin bulk form.

Result

A central composite design was employed to optimize the percent of methanol in the mobile phase and flow rate for the analysis of a compound esculin using the RP-HPLC method. The optimized conditions were 43% methanol and 0.9 ml/min flow rate, with a retention time of 3.78 min, and Phenomenex Luna (5 µm × 250 mm, 4.6 mm) column was used. The method was found to be linear with a correlation coefficient of 0.9998 for a concentration range of 4–20 μg/ml. The parameters of the system suitability test were within the acceptable range (0.0612–0.1398%), and the precision for both intra-day and inter-day measurements was below 2%. The robustness and ruggedness of the method were also good, with changes in the flow rate and mobile phase composition having a minimal impact on the method's performance. The limit of detection (LOD) and limit of quantification (LOQ) values were reported to be 0.82891 μg/ml and 2.511 μg/ml, respectively. The validation parameters of the method adhered to the specified limit following the ICH guidelines.

Conclusion

In summary, an AQbD-based efficient and robust RP-HPLC chromatographic method has been developed for the quantification of the esculin compound. The method is linear, precise, and reproducible, and it has good LOD and LOQ values. The method could be used for repetitive analysis of the compound in pharmaceutical formulations.