Isocratic RP-HPLC method for rutin determination in solid oral dosage forms

A rapid and sensitive assay for quantitative determination of rutin in oral dosage forms based on isocratic reversed phase high performance liquid chromatography (RP-HPLC) was developed and validated. Using a C18 reverse-phase analytical column, the following conditions were chosen as optimal: mobile phase methanol–water 1:1 (v/v), pH 2.8 (adjusted with phosphoric acid), flow rate = 1 mL min−1 and temperature T = 40.0 °C. Linearity was observed in the concentration range 8–120 μg mL−1 with a correlation coefficient of 0.99982 and the limit of detection (LOD) = 2.6 μg mL−1, and limit of quantification (LOQ) = 8.0 μg mL−1. Intra- and inter-day precision were within acceptable limits. Robustness test indicated that the mobile phase composition and pH influence mainly the separation. The proposed method allowed direct determination of rutin in pharmaceutical dosage forms in the presence of excipients, but is not suitable for preparations where compounds structurally/chemically related to rutin may be present.