Experimental Materials and reagentsNisoldipine was supplied from NODCAR, Egypt, and its pharmaceutical form Sular tablets were manufactured by Rizhao Highrun Biotechnology Co., Ltd, China. All reagents and chemicals of the highest purity and analytical grade were available. Potassium dihydrogen phosphate and HPLC grade methanol were purchased from VWR. Hexane sulphonic acid sodium salt was obtained from Sigma-Aldrich. A standard stock solution 100 µg/ml of Nisoldipine was prepared in 100 ml methanol as solvent. Working solutions were prepared separately by making serial dilutions from the standard solution to obtain calibration graph in the range of 5-30 µg/ml. These solutions were stored at 20°C. Once prepared, analyzed daily for inter and intra-day variations of the method. 20 µl of these solutions were injected into LC system and chromatographic. Chromatographic conditionsHigh performance liquid chromatography experiments were carried out using the model of LC system Agilent 1100 Series with degasser, quaternary pump, auto-sampler, column heater, UVdetector and Chemstation-software. The detector was set to scan from 200 to 500 nm and had a discrete channel set at 275 nm, which was the AbstractIn this study, novel high performance liquid chromatography methods which are described as a simple, selective, sensitive, precise and simultaneous analysis of Nisoldipine in bulk and commercial tablet formulation containing Nisoldipine. Good chromatographic separation was achieved using a specific column Agilent ZORBAX Eclipse Plus C18, 4.6×250 mm and a mobile phase consisting of methanol, 0.01 M potassium dihydrogen phosphate aqueous solution and 0.1 M Hexane sulphonic acid sodium salt (25:65:10, v/v) at pH 4.0 using orthophosphoric acid with a flow rate of 1.0 ml/min. The ultraviolet detector was set at a wavelength of 275 nm. Nisoldipine was eluted at 7.43 min. Due to the high precautions taken during the analysis, no extraneous materials were found to interfere. The linear range for Nisoldipine was 5-30 µg/ml. The linearity, precision, accuracy, robustness, limit of detection and limit of quantification of the proposed method were determined. Regression coefficients (r 2 ≥ 0.999), recovery (97.2-103.1%), the limit of detection (0.4 µg/ml) and the limit of quantification (1.0 µg/ml) were validated and found to be satisfactory. The proposed method is convenient for quantitative routine analysis and purity control of Nisoldipine in its bulk powder and dosage forms.