Febuxostat is a selective inhibitor of xanthine oxidase that is used for the treatment of hyperuricaemia in patients with gout. An isocratic liquid chromatographic method was developed and validated for the determination of febuxostat. Chromatographic separation was achieved on a C18 column using sodium acetate buffer (pH 4.0)-acetonitrile (40:60, v/v), with a flow rate 1.2 mL/min (ultraviolet detection at 254 nm). Linearity was observed in the concentration range of 0.1-200 µg/mL (R(2) = 0.9999) with a linear regression equation of y = 21148x - 2025.1. The limit of quantification was found to be 0.0783 µg/mL and the limit of detection was found to be 0.0257 µg/mL. Febuxostat was subjected to stress conditions of degradation in aqueous solutions, including acidic, alkaline, oxidation, photolysis and thermal degradation. The forced degradation studies were performed by using sodium hydroxide, hydrochloric acid, hydrogen peroxide and thermal and ultraviolet radiation. Febuxostat is more sensitive toward acidic conditions than oxidation and very resistant toward alkaline, thermal and photolytic degradations. The method was validated as per the guidelines of the International Conference on Harmonization. The intra-day and inter-day precision (relative standard deviation) was found to be 0.29-0.41 and 0.63-0.76, respectively. The method is simple, specific, precise, robust and accurate for the determination of febuxostat in pharmaceutical dosage forms (tablets).

Trifluridine, also known as trifluoro thymidine is an anti-viral drug used for the treatment of viral infections of eyes. A new validated RP-UFLC method has been developed for the determination of Trifluridine using Shimadzu Model UFLC system SPD-M20A 230V with PDA detector and LC- 20AD pumps and C18 Shim-pack GWS HPLC packed column (250 mm × 4.60 mm, 5 μm) in in ophthalmic preparations. Mobile phase consisting of acetonitrile: 10 mM potasium dihydrogen phosphate buffer adjusted pH to 3.5 with dilute tri fluro acetic acid (70:30 v/v) (Isocratic mode) with 1.0 mL/min flow rate (Detection wavelength 272 nm) are the chromatographic conditions for the present study. Trifluridine obeys Beer-Lambert’s law over the concentration range 0.1-120 µg/mL with linear regression equation y = 46195x – 1876.5 (R² = 0.9998) and the method was validated as per ICH guidelines. The LOQ and LOD values were found to be 0.08934 µg/mL and 0.0257 µg/mL respectively. Trifluridine was exposed to different stress conditions such as alkaline hydrolysis, acidic hydrolysis, oxidation and thermal degradation and the assay was carried out. The proposed method is simple, precise, accurate, robust and used for the routine analysis of marketed formulations.

Budesonide is a glucocortico steroid used for the treatment of nasal polyposis, asthma and Crohn’s disease. A stability indicating RP-HPLC method has been developed and validated for the quantification of Budesonide in pharmaceutical dosage forms in presence of an internal standard, Etoricoxib. Mobile phase including a mixture of formic acid: acetonitrile: methanol (25: 10: 65) was chosen for the chromatographic study with flow rate 1.0 ml/min. The PDA detection was carried at 240 nm and the elution was achieved on isocratic mode using Zorbox C18 column. Beer-Lambert’s law was obeyed over a concentration range 0.05-120 µg/ml and the linear regression equation was y = 0.0489x + 0.003 with correlation coefficient 0.9997). The LOQ and LOD was found to be and 0.0393 and 0.1192 µg/ml. Stress degradation studies such as acidic hydrolysis, alkaline hydrolysis, oxidation and thermal degradation were performed. The method was validated for the parameters linearity, precision, accuracy, robustness as per ICH guidelines and the proposed stability indicating liquid chromatographic method was found to be simple, accurate, precise and robust and can be applied for the assay Budesonide formulations.