A validated new stability indicating densitometric method for quantitative analysis of glipizide in tablets

A sensitive, precise, specific, linear, and stability-indicating high performance thin-layer chromatographic (HPTLC) method has been established and validated for quantitative analysis of one of the antidiabetic agents, the sulfonylurease glipizide in active pharmaceutical ingredient (API) and in tablet formulation, using toluene: methanol (8:2; v/v) as mobile phase. Chromatographic separation was achieved on precoated silica gel 60F254 plates with 0.2 mm thickness. Detection and quantification were performed by classical densitometry using a UV detector at 230 nm. Compact spots were obtained for glipizide (RF 0.35± 0.02, mean ± SD). Calibration plots were constructed in the range 100-700 ng per band and were linear with good calibration coefficients (r =0.9997 ±0.01, mean ± SD) for glipizide. The limit of detection and quantification were 100 and 300 ng per spot for glipizide. Glipizide was subjected to the International Conference on Harmonization (ICH) prescribed hydrolytic (acid, base, and neutral), oxidative, photolytic, and thermal stress conditions. Among all the above mentioned conditions, the drug was found to be susceptible to some stress conditions. However, the degradation products were well resolved from the pure drugs with significantly different RF values.