[3�C6] Moreover simultaneous Ultraviolet (UV) estimation of OLM and Amlodipine has been reported by Kumar M et al., but a single estimation of this drug has not been reported in bulk or in pharmaceutical formulation. Thus, the present study was undertaken to develop www.selleckchem.com/products/CP-690550.html and validate a simple, sensitive, accurate, precise, and reproducible UV method for OLM, and also to perform stress degradation studies on the drug as per ICH Guidelines, using the same method.[7�C14] MATERIALS AND METHODS Instruments and materials The instruments used were a SHIMADZU 1700 double beam UV / Visible Spectrophotometer and a SHIMADZU AX200 analytical balance. The OLM pure drug was obtained from the Torrent Research Center, Bhat, Gandhinagar, as a gift sample, with 99.9% w/w assay value, and was used without further purification.

All chemicals and reagents used were of analytical grade. The OLM tablets (40 mg) were purchased from the local market with a trade name Benicar? (Daiichi Sankyo). Preparation of the standard stock solution A standard drug solution of OLM was prepared by dissolving 10 mg of OLM in 10 ml methanol, and this was transferred into a 100 ml volumetric flask. The volume was brought up to the mark with methanol to obtain a stock solution of OLM with 100 ��g/ml final concentration. The solution was further sonicated for 15 minutes to obtain a clear solution. Preparation of the working solution From the above stock solution, a 2 ml sample was transferred into a 10 ml volumetric flask and the volume was made up to the mark with methanol to prepare a concentration of 20 ��g/ml.

The sample was further scanned by a UV-VIS Spectrophotometer in the range of 200 �C 400 nm, using methanol as a blank. The wavelength corresponding to the maximum absorbance (��max) was found to be 257 nm [Figure 2]. This was further utilized to obtain a calibration curve. Figure 2 UV spectrum of Olmesartan medoxomil in methanol Preparation of the calibration curve Aliquots of 0.2 to 2 ml stock solutions were transferred to a series of 10 ml volumetric flasks, with subsequent volume adjustment by methanol up to 10 ml. The solutions were scanned in a double beam UV-VIS spectrophotometer. The samples were analyzed for their respective absorbance at 257 ��max. The calibration curve was plotted and the optical characteristics summarized [Table 1].

Table 1 Validation parameters Preparation of the sample solution The proposed GSK-3 method was applied to analyze the commercially available OLM tablet (Benicar?�C40 mg). Ten tablets were weighed and powdered. The amount of tablet powder equivalent to 10 mg of OLM was weighed accurately and transferred to a 100 ml volumetric flask containing 10 ml of methanol, which was further sonicated for 15 minutes with frequent shaking. The volume was brought up to 100 ml by methanol.