Pankaj B. Miniyar

A new reverse phase high performance liquid chromatography (RP-HPLC) method for the quantitative determination of Sitagliptin in human plasma was developed and validated as per US-FDA guidelines. The drug was spiked in the plasma and extracted with mobile phase by precipitation method. The extracted analyte was injected into an INTERSIL C18 column (150 mm × 4.6 mm, 5μm), maintained at ambient temperature and effluent was monitored at 267 nm. The mobile phase consisting of acetonitrile: methanol: buffer (2:3:5 v/v). The pH of the mobile phase was adjusted to 4.0 by using O-phosphoric acid. The flow rate was maintained at 1.0 mL/min. The developed method shows high specificity for sitagliptin. Calibration curve was plotted with a range from 25-125µg/mL (r2>0.9994). The lower limit of quantification (LLOQ) was found to be 25μg/mL. The method was validated for parameters like accuracy, precision, recovery, linearity, range, stability and sensitivity. This RP-HPLC method is suitable for determining the concentration of sitagliptin in human plasma and it was applied to routine analysis for determination of the Sitagliptin from dosage form during pharmacokinetic study.

A simple reverse phase liquid chromatographic method has been developed and subsequently validated for simultaneous determination of Ofloxacin and Ornidazole in infusion dosage form. The separation was carried out using a mobile phase containing methanol and buffer (equal proportion of 0.01M orthophosphoric acid and 0.01M sodium phosphate monobasic dihydrate) with pH 4.00 adjusted by 20% of triethylamine in the ratio of 60:40 v/v. The column used was HiQ Sil C18 (150 mm x 4.6 mm i.d, 5 µ) with flow rate of 1 mL / min using UV detection at 300 nm. The described method was linear over a concentration range of 1.25-10 µg/mL (r2>0.9991) for Ofloxacin and 3.12-25 µg/mL (r2>0.9992) for Ornidazole. Separation was achieved within 5 min. The mean % recovery was found to be 99.94% for Ofloxacin and 100.27 % for Ornidazole. The limit of detection (LOD) for Ofloxacin and Ornidazole were found to be 0.146 and 0.25 µg/mL respectively. Whereas the limit of quantification (LOQ) for Ofloxacin and Ornidazole was 0.44 and 0.77 µg/mL respectively. The results of the study showed that the proposed RP-HPLC method is simple, rapid, precise, accurate and cost effective which is useful for the routine determination of Ofloxacin and Ornidazole in bulk drug and in its infusion.