A novel, simple, sensitive and stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the quantitative determination of the geometric isomer (Trans) and other related substances in the active pharmaceutical ingredient (API) of Tafluprost (TFL), with their determination by an assay. A chromatographic separation of TFL and its impurities was achieved with a C18 analytical column, using gradient elution with mobile phase A consisting of a mixture of water, methanol and orthophosphoric acid (900:100:1, v/v) and mobile phase B consisting of a mixture of acetonitrile and water (900:100, v/v). The instrumental settings included a flow rate of 1.0 mL/min for related substances and 1.2 mL/min for the assay, a column temperature of 50°C and a detector wavelength of 210 nm, using a photodiode array detector. TFL was exposed to thermal, photolytic, hydrolytic and oxidative stress conditions and the stressed samples were analyzed by the proposed method. Peak homogeneity data of TFL were obtained by using a photodiode array detector in the stressed sample chromatograms, which demonstrated the specificity of the method for estimation in the presence of degradants. The developed method was validated for parameters such as precision, accuracy, linearity, limit of detection, limit of quantification, ruggedness and robustness as per ICH guidelines.

Medical science is a field of study that is relevant to all people, but the development of pharmaceutical, biomedical and life science is of particular importance. In these fields, further studies are being established to determine with incredible accuracy the quantities and concentration of inorganic elements and organic compounds, such as nucleotides, sulphur and phosphorous containing peptides and proteins, to be used in all kinds of drugs. Since 1980, inductively coupled plasma-mass spectrometry (ICP-MS) has emerged as a new and powerful technique for elemental and isotopic analysis. It provides a means for the analysis of an extremely wide range of elements and the co-analysis of most elements in the periodic table. It can also be used for qualitative, quantitative and semiquantitative analysis and for the measurement of isotopic ratios through mass-to-charge ratios. In recent years, ICP-MS has emerged as the best technique for the quantification of inorganic impurities in pharmaceutical and biomedical applications. This chapter focuses on introducing the applications of ICP-MS in the pharmaceutical and biomedical fields. Some problems facing ICP-MS are also presented at the end of this chapter.

A novel, rapid, specific and stability-indicating reverse-phase high-performance liquid chromatography method was developed for the quantitative determination of related compounds, obtained from two different synthetic routes and degradation products of Azilsartan kamedoxomil (AZL). The method was developed by using a YMC-Pack pro C18 (150 × 4.6 mm, 3 µm) column with a mobile phase containing a gradient mobile phase combination. The eluted compounds were measured at wavelength 220 nm. The developed method run time was 25 min, within which AZL and its eight impurities were well separated with minimum 3.0 resolution. The drug substance was subjected to stress conditions of hydrolysis (acid, base and water), oxidation, photolysis, sunlight, 75% relative humidity and thermal degradation as per International Conference on Harmonization (ICH) prescribed stress conditions to ascertain the stability-indicating power of the method. Significant degradation was observed during acid, base, peroxide, water hydrolysis and 75% relative humidity studies. The mass balance of AZL was close to 100% in all the stress condition. The developed method was validated as per the ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness.

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A simple kinetic method has been developed based on the autoxidation of o-hydroxyphenylthiourea to disulphide, which is catalysed by trace amounts of cobalt. The reaction is monitored spectrophotometrically at pH 8.0 and cobalt is determined effectively in the range 5-50 ng ml-l. This method has been used to determine trace amounts of cobalt present in certain plant materials such as carrot roots and corn grains, in which it plays a vital role in different physiological activities.