K. Raghu Babu

A sensitive and rapid HPLC method was developed and validated for the determination of potential genotoxic impurities i.e (Bromomethyl)biphenyl methyl ester and (Dibromomethyl)biphenyl methylester at trace level in Telmisartan drug substance by applying the concept of threshold of toxicological concern (TTC). The HPLC method was developed and optimized on Symmetry Shield RP18, 3.5 m (150mm × 4.6mm) column with oven temperature maintaining at 40°C and 0.02M Phosphate buffer pH 2.5 was chosen as mobile phase A and mixture of acetonitrile and Phosphate buffer (55:45) was selected as mobile phase B in gradient reverse phase mode in isocratic mode of composition. Chromatographic parameters i.e flow rate: 1.0 ml/min, wavelength detection: 205 nm, injection volume: 20µl and run time: 25 min were applied in this methodology.  Based on validation data, the method is found to be specific, sensitive, accurate and precise. The established limits of Limit of detection and Limit of quantification for subjected impurities are found to be 2.4 µg/g and 4.7 µg/g respectively for each impurity. The recovery at LOQ level obtained was 98.2% for (Bromomethyl) biphenyl methyl ester and 99.2% for (Dibromomethyl) biphenyl methyl ester. This method can be used as good quality control tool for quantization of these impurities at low level. The experimental results are discussed in detail in this research paper.

A gradient reversed phase high performance liquid chromatography (RP-HPLC) method has been developed and validated for the determination for related substances of Dapagliflozin drug substance. Chromatographic separation of Dapagliflozin from its process and degradation related substances was achieved on YMC Pack Pro C18, 250mm × 4.6mm 5m i.e A stainless steel column 250 mm long, 4.6 mm internal diameter filled with Octadecyl silane chemically bonded to porous silica particles of 5 mm diameter maintained column oven temperature at 25°C. Orthophosphoric acid buffer is mobile phase A and acetonitrile is mobile phase B. Wavelength for UV detection: 225nm, flow rate: 0.8 ml/min and Injection volume: 20µl. The developed method suitability was checked and validated as per ICH guidelines for specificity, linearity, accuracy, precision, limit of quantification, limit of detection robustness and ruggedness experiments. Dapagliflozin drug substance was subjected to stress conditions of thermal, hydrolysis, humidity, peroxide and photolytic to observe the degradation products. Limit of detection of each RS is less than 0.008%w/w indicating that the developed method is highly sensitive. The experiment results are given in detailed in this research article.