Isolation and characterisation of nateglinide and its impurity in bulk and marketed formulation by HPTLC method

The samples were applied on to the plate in the form of band with band length of 5mm. The mobile phase consisted of Chloroform: Methanol in the ratio of 8:2 v/v and 10ml of the mobile phase was used in each chromatographic run. Ascending development technique was carried out in a twin trough chamber saturated with mobile phase vapours for 15 min. The multiple wavelength detector was set at 216 nm, and quantification of the analyte was based on measuring its peak area. Rf for NTG was about 0.59. Calibration curve of NTG was linear in the range 100-600μg/band with correlation coefficient >0.9994. The drug was subjected to forced-degradation conditions of reaction, oxidization and dry heat. Unknown impurity was found in Nateglinide industrial batch stability condition at levels more than 0.1% in HPTLC analysis was characterized preliminarily by ESI-MS/MS studies. The major unknown (unknown-1 and 2) were enriched and isolated by preparative LC and structure was evidenced by 1H NMR spectroscopy, mass spectrometry and FT-IR. This technique will be used for the standard management of each drug substance and drug product. Finally, the projected method made use of hyphenated techniques as a tool for peak identity and purity confirmation.