A Validated specific Stability-Indicating Reversed-Phase High-Performance Liquid Chromatography Assay Method for L-Ornithine L-Aspartate and Silymarin, and their related Substances and its Application to Dissolution Studies

Abstract

The present study was aimed at the development and successive validation of a novel, simple, sensitive, and stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method for quantitative calculation of L-ornithine L-aspartate (LOLA) and Silymarin (SL), and also their relevant substances in bulk and pharmaceutical dosage forms. The chromatographic technic was optimized using the impurity-spiked solution. The separation of all the two active components and their impurities was achieved by a chromatographic method with an Agilent Eclipse XDB-C18, 150 × 4.6 mm, 3.5 μ column, using gradient elution with mobile phase A consisting of a mixture of 0.1% orthophosphoric acid and water and acetonitrile as mobile phase B. The instrumental settings included a flow rate of 1 mL/min for both related substances and assay, a detector wavelength of 225 nm, by using a PDA detector. The established method was validated according to the current ICH requirements. The detection limit and the limit of quantification for the two active components and their related impurities were established with respect to test concentration. The calibration graphs plotted were linear with a regression coefficient R2 andgt; 0.999, indicates the linearity of the method was within the limits. Recovery studies were satisfactory and the parameters, such as, specificity, linearity, accuracy, precision, and robustness were determined as part of the method validation. Moreover, using the same method dissolution study was performed on active pharma ingredients to estimate the recovery. The obtained results were within the range of acceptance criteria. These results suggest that the developed method was found to be applicable for routine analysis for testing chromatographic purity of LOLA and SL and it can be utilized for the calculation of both active ingredients and their impurities in tablet dosage forms.