Development and validation of stability indicating RP-HPLC method for simultaneous determination of aloin and aloe-emodin

Aloe vera (Liliaceae) extracts, aloin and aloe emodin were simultaneous analysed by the development and validation of a sensitive precise and stability indicating HPLC method. Reversed phase chromatography was performed on a Cl 8 column with methanol-water, 1: 1 (%, v/v), as mobile phase at a flow rate of 0.5 mL min"¹. Detection was performed on fluorescence detector at existing wave length (410 nm) and emitting wave length (510 nm). Sharp peaks were obtained for aloin and aloe emodin at a retention time of 7.5 ± 0.04 min and 21.3 ± 0.15 min, respectively. Linear regression analysis data for the calibration plot showed a good linear relationship between response and concentration in the range 0.25 |ig mL"¹ to 1.1 |ig mL"¹ for both aloe emodin and aloin. The regression coefficient for aloe emodin and aloin were 0.9996 and 0.9909, respectively. The detection (Limit of detection - LOD) and quantification (Limit of quantification - LOQ) limits for aloe emodin and aloin were 0.2 |ig mL"¹ and 0.25 |ig mL"¹, respectively. The method was validated in accordance with ICH guidelines for accuracy, precision, reproducibility, specificity, robustness, limits of detection and quantification. Statistical analysis proved the method was precise, reproducible, selective, specific and accurate for the analysis of aloin and aloe emodin. The wide linearity range, sensitivity, accuracy short retention time and simple mobile phase implied that the method showed high precision and accuracy and suitable for routine quantification of aloin and aloe emodin.