Systematic development and validation of RP-HPLC method for simultaneous estimation of tamoxifen and sulphoraphane with specific application for nanolipidic formulations

Tamoxifen (TAM) and Sulphoraphane (SFN) are well-known anti-estrogen drugs used for the treatment of breast cancer. Due to their synergistic therapeutic potential, their combination is preferred as it helps to minimize the drug-related toxicities and enhances therapeutic efficacy. A simple, robust and fast simultaneous reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed as well validated for the analysis of both the drugs based on their particular wavelength. The separation was performed on C-18 analytical column with dimensions of 4.6 x 250 mm, 5 mu m using mobile phase methanol: water (pH 3.5) in the ratio 70:30 and flow rate of 0.8 min/mL. Box-Behnken experimental design was used to optimized these independent variables and analyze their effect on the response variables like retention time (RT), no. of theoretical plates and tailing factor of both analytes. Method validation was carried out for establishing the specificity, linearity range, accuracy, sensitivity, robustness, precision and ruggedness. The method applicability was evaluated on different nanoformulations, i.e., solid lipid nanoparticles (SLNs), liposomes (LIPO), nanostructured lipid carriers (NLCs). The peaks of the analyte were found to be well resolved and two distinct RT were recorded for TAM and SFN. Calibration curves were found to be linear for TAM and SFN over concentration range of 6-24 mu g/mL. All method validation criteria were within the range of acceptance. Relative standard deviation (%RSD) was observed to be <2% for inter- and intra-day precision. The application of developed method for estimation of drugs from the nanoformulations was suitabile for in nitro as well as in vivo studies. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of King Saud University.