Quality assessment and analytical quality by design-driven RP-HPLC method development for estimation of Gymnemagenin in Gymnema sylvestre

Abstract

Gymnemic acids are the group of phytocompounds from Gymnema sylvestre known to possess hypoglycemic activity. Quantitative estimation of Gymnemic acid in terms of Gymnemagenin is essential for the standardization of G. sylvestre. In the present work, methodology combining reversed-phase HPLC with an Analytical Quality by-design approach was utilized for quantitative analysis of Gymnemagenin in G. sylvestre leaves. The quality assessment was performed by evaluating various pharmacognostic parameters as per WHO guidelines. Initially, the Analytical Target Profile and Critical Quality Attributes were identified. The method was optimized using 22 full factorial designs with a concentration of orthophosphoric acid in the aqueous phase (X1) and mobile phase ratio (X2) selected as an independent variable and, tailing factor (R1) and theoretical plates (R2) chosen as dependent variables. The optimized chromatographic conditions were identified with mobile phase, Methanol and Water (0.1% OPA) in the ratio of 85:15 v/v with flow rate of 0.8 mL/min and detection wavelength of 210 nm. Further, the amount of Gymnemagenin in crude G. sylvestre leaves and its extract was found to be 5.108% and 6.23% w/w respectively. The quality evaluation parameters were found to be within the given standard limit. Finally, it can be concluded that the combination of the HPLC method with the AQbD approach resulted in a more precise and accurate method for quantification of total Gymnemic acids in terms of Gymnemagenin. The developed method involves advantages such as efficient separation, well-defined peaks, and reduced analytical time and can be successfully applied for the analysis of Gymnemagenin in different Gymnema species and their herbal products.