D. Ramachandran

A new, simple, rapid, selective, precise and accurate isocratic reverse phase high performance liquid Chromatography assay method has been developed for estimation of Fumaric acid in Quetiapine hemi fumarate drug substance. The separation was achieved by using column Hypersil C18 (250×4.6mm, 5µm), in mobile phase consisted of acetonitrile and pH 3.0 phosphate buffer, adjusted to pH 3.0 with the help of dilute orthophosphoric acid in the gradient elution. The flow rate was 1.0 mL/min-1 and the separated Fumaric acid was detected using UV detector at the wavelength of 210 nm. Column temperature 25°C and sample temperature ambient and injection volume 20µl. The retention time of Fumaric acid, was noted to be 3.65 min respectively, indicative of rather shorter analysis time. The method was validated as per ICH guidelines. The proposed method was found to be accurate, reproducible, and consistent.

A new, simple, rapid, selective, precise and accurate isocratic reverse phase high performance liquid Chromatography assay method has been developed for simultaneous estimation of Isoniazid and Pyridoxine tablet formulations. The separation was achieved by using column Hypersil BDS, (250 x 4.6 mm, 5 µ) (Make: Thermo), in mobile phase consisted of pH4.0 phosphate buffer and Acetonitrile in the ratio of 75:25 v/v. The flow rate was 1.0 mL/min, column oven temperature 30° C, the injection volume was 10 μL, and detection was performed at 267 nm using a photodiode array detector (PDA), Run time 6 minutes. The retention time of Isoniazid and Pyridoxine, was noted to be 3.5 minutes and 4.3 minutes respectively, indicative of rather shorter analysis time. The method was validated as per ICH guidelines. The proposed method was found to be accurate, reproducible, and consistent.

A new, simple, rapid, selective, precise and accurate isocratic reverse phase ultra performance liquid Chromatography assay method has been developed for estimation of Lamivudine in tablet formulations. The separation was achieved by using column Acquity UPLC BEH Phenyl (100×2.1mm, 1.7µm), in mobile phase consisted of pH 3.8 ammonium acetate buffer and methanol. The flow rate was 0.5mL.min-1 and the separated Lamivudine was detected using UV detector at the wavelength of 277 nm. The retention time of Lamivudine was noted to be 2.50 min respectively, indicative of rather shorter analysis time. The method was validated as per ICH guidelines. The proposed method was found to be accurate, reproducible, and consistent.

A new simple, accurate, rapid and precise isocratic RP-HPLC was developed and validated for the determination of Rosuvastatin and Ezetimibe in Pharmaceutical tablet dosage form by droping method. The Method employs Shimadzu LC system on Hypersil ODS column (4.6 x 250 mm, 5 µm) and flow rate of 1.5ml/min with an injection volume 20µl.  Buffer, Acetonitrile and Methanol was used as mobile phase in the composition of 40:30:30v/v. The Detection was carried out at 230nm. Linearity ranges for Rosuvastatin and Ezetimibe were 11-33µg/ml, 10-30µg/ml respectively for HPLC. Retention Time of Rosuvastatin and Ezetimibe were found to be 3.7 and 5.7 min respectively. Percent Recovery study values of Rosuvastatin and Ezetimibe were found 99.6-101.1% and 99.9-100.7% respectively. This newly developed method i.e. droping method was successfully utilized for the Quantitative estimation of Rosuvastatin and Ezetimibe in tablet dosage form. This method was validated for selectivity, accuracy, precision, and linearity, Ruggedness, Robustness and Stability Studies as per ICH guidelines.

(6-(3,4-diaminophenyl)-5-methyl-4,5-dihydropyridazine-3(2H)-one(GTI-A) and p-anisaldehyde (GTI-B)have been highlighted a (GTI's) potential genotoxic impurities (PGIs) of Pimobendan. A sensitive RP-HPLC method was developed and validated for the determination of (6-(3,4-diaminophenyl)-5-methyl-4,5-dihydropyridazine-3(2H)-one and p-anisaldehyde in pimobendan using Zodiac C18 (125 X 4.6mm 5µ) column, with UV Detector. The calibration curves showed good linearity over the concentration range of 0.5μg/mL to 1.5μg/mL with respect to the sample. The correlation coefficient was 0.999. Excellent recoveries of 102 % were obtained at the level of 0.5μg/mL.

A new, simple, rapid, selective, precise and accurate isocratic reverse phase high performance liquid Chromatography assay method has been developed for estimation of Curcumin in tablet formulations. The separation was achieved by using column Hypersil BDS C18, 150x4.6 mm, 5µ (Make: Thermo), in mobile phase consisted of tetrahydrofuran and citric acid buffer in the ratio of (550:450, v/v). The flow rate was 1.0 mL.min-1 and the separated curcumin was detected using UV detector at the wavelength of 425 nm. The retention time of curcumin, was noted to be 8.05 min respectively, indicative of rather shorter analysis time. The method was validated as per ICH guidelines. The proposed method was found to be accurate, reproducible, and consistent.

  A rapid and sensitive UV-Visible spectroscopic method was developed for the estimation of Ranalozine in pure and its Pharmaceutical formulations. The method was validated as per International Conference on Harmonization [ICH] guidelines. The Ranalozine was monitored at 230nm with UV detection and there is interference of diluent at 230nm for Ranalozine. The method was linear (r2 =0.999) at concentration ranging from 12 to 40μg/ml, precise (intra-day relative standard deviation [RSD] and inter-day RSD values < 1.0%), accurate (mean recovery = 100.2%), specific and robust. The results showed that the proposed method is suitable for the precise, accurate and rapid determination of Ranalozine in bulk, its capsule dosage forms. Key Words: Ranalozine, UV-Visible spectroscopy, Validation, Dosage form.