Determination and in-process control of zolpidem synthesis by high-performance liquid chromatography

A high-performance liquid chromatographic assay with diode-array detection has been developed for the in-process control of zolpidem synthesis and for the analysis of the drug and its synthetic intermediates. The separation uses a 4.6mm i.d. reversed-phase Kromasil C(18) (150 mm) column, 5 microm particle size with a gradient elution mode of acetonitrile and 0.02 M NH(4)OAc (adjusted to pH 8.0) as the mobile phase (flow rate 1.0 mlmin(-1)). The analysis is performed in 12 min. The method is simple, rapid and highly specific.

In-process control of midazolam synthesis by HPLC

A high-performance liquid chromatographic assay coupled with UV detection (239 nm) has been developed for the determination of midazolam and its synthesis precursors. The separation of the analytes was performed on a Kromasil C8 column (15 cm x 4.6 mm i.d., 5 microm) at 30 degrees C. The mobile phase [ammonium chloride (pH 5.5, 1 g l(-1))-methanolacetonitrile (45:22:33, v/v/v)] was pumped at a flow-rate of 1.5 ml min(-1). This method is rapid (less than 11 min), sensitive (limit of detection (LOD) ranged between 0.05 and 0.5 mg l(-1)) and selective for the determination of midazolam, and it could be used for monitoring different synthetic routes.

HPLC for in-process control in the production of sultamicillin

A high-performance liquid chromatographic assay coupled with UV detection (215 nm) was developed for the determination of sultamicillin and its synthesis precursors. The separation of the analytes was performed on a Kromasil C(18) column (15 cm x 4.6 mm i.d., 5 microm) at 20 degrees C. The mobile phase (25 mM phosphate buffer, pH 7.0 and acetonitrile 48%) was pumped at a flow rate of 1.0 ml min(-1). This method is sensitive (limits of detection ranged between 0.4 and 1.2 mg l(-1)) and selective for the determination of sultamicillin and could be used for monitoring different synthetic routes.