Abstract

METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF AMLODIPINE AND INDAPAMIDE BY DIFFERENT ANALYTICAL METHODS IN BULK AND PHARMACEUTICAL DOSAGE FORM

Gurran Chandu Priya, K. Thejomoorthy*, Ch Saibabu

ABSTRACT

A simple, accurate and precise methods have been developed and validated according to ICH guidelines for estimation of silymarin in herbal dosage form by UV-Spectrophotometric, and RP-HPLC methods. First method is based on simultaneous estimation using two wavelengths, 365 nm (λmax of AMLO) and 279 nm (λ max of INDA) by simultaneous equation method. The second method involves the use of first order derivative technique, here 293 nm, the zero crossing point of AMLO, 279 nm, the zero crossing point of INDA were used for the estimation. The third method is based on Q-absorption Ratio method using two wavelengths 365 nm (λmax of AMLO) and 312 nm (Isoabsorptive point). In the dual wavelength method two wave lengths 270 nm and 288 nm were selected as λ1 and λ2 for the estimation of AMLO, INDA shows the same absorbance at these wavelengths. Similarly, wavelengths 350 nm and 378 nm were selected as λ1 and λ2for the estimation of INDA, AMLO shows the same absorbance at these wavelengths. Colorimetry: The method is based on use of MBTH reagent for simultaneous estimation of AMLO and INDA using two wavelengths, 626 nm (λmax of AMLO) and 600 nm (λmax of INDA). All the five methods obeys Beer’s linearity in the concentration range of 10-50 μg/ml for AMLO and 5-25 μg/ml for INDA respectively. RP-HPLC Method: A simple, accurate and sensitive HPLC method was developed for estimation of silymarin. The chromatographic separation was carried out on RP C18 column (250 × 4.6 mm, 10 μm) using mobile phase, phosphate buffer: water (65:35 % v/v) pumped at a flow rate of 1 ml/min. The eluent was monitored at 288 nm. The method is specific and linear over the range of 10-200 ng/ml. The method was statistically validated for precision, accuracy, robustness and recovery. The HPLC method can be applied for identification and quantification of silymarin in herbal formulations.

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