Development and Validation of Selective High-Performance Liquid Chromatographic Method Using Photodiode Array Detection for Estimation of Aconitine in Polyherbal Ayurvedic Taila Preparations

A simple, sensitive, and selective high-performance liquid chromatographic (HPLC) method has been developed and validated for the analysis of aconitine in marketed ayurvedic taila (oil) formulations containing roots of Aconitum chasmanthum. Chromatography of methanolic extracts of these formulations was performed on C18 (5？μm × 25？cm × 4.6？mm i.d.) column using isocratic mobile phase consisting of (65？:？35% v/v) acetonitrile and buffer solution (aqueous 0.01？M ammonium bicarbonate buffer, adjusted to pH 9.6 using 30% ammonia solution) at a flow rate of 1？mL/min and SPD-10 photodiode array (PDA) UV-Visible detector. The analytical reference, aconitine, was quantified at 238？nm. The retention time of aconitine was about 42.54？min. The linear regression analysis data for the calibration plot showed a good linear relationship with correlation coefficient of 0.9989 in the concentration range of 15 to 90？μg/mL for aconitine with respect to peak area. The limit of detection and limit of quantitation values were found to be 0.03？μg/mL and 0.1？μg/mL respectively. Repeatability of the method was found to be 0.551–1.689 RSD. Recovery values from 97.75 to 99.91% indicate excellent accuracy of the method. The developed HPLC method is accurate and precise and it can be successfully applied for the determination of aconitine in marketed ayurvedic oil formulations containing Aconitum chasmanthum. 1. Introduction Aconitum chasmanthum (Family, Ranunculaceae) is a most valuable medicinal plant, widely used in the traditional and folk medicines of a number of countries of south east Asia. The chief chemical constituents of Aconitum chasmanthum root are aconitine, mesaconitine, and hypaconitine, and their respective hydrolyzed analogs are called monoester alkaloids, that is, benzoylaconine, benzoylmesaconine, and benzoylhypaconine [1–3]. Aconitine being the major diterpenoid responsible for the biopotency of Aconitum chasmanthum is recognized as the reference compound [3, 4]. Many polyherbal oil formulations in Indian and Chinese traditional systems of medicine used for control of skin diseases contain aconitum root as major active ingredient [5, 6]. Polyherbal oil formulations are made with the main objective of incorporating the fat-soluble fraction of the component of herbal drugs to a suitable oil base. Standardization of these formulations in terms of composition is important to ensure quality and safety. Aconitine can be used as analytical reference in the quality control of polyherbal oil formulations containing Aconitum chasmanthum [7–10]. There are reports on the