Analytical method development and validation of residual solvents in ethosuximide by GC – headspace technique

A precise, reliable GC approach has been created for estimating the amount of isopropyl alcohol (class-III
residual solvent) content in ethosuximide by GC-headspace technique. The chromatographic separation was
carried out using dimethyl acetamide as the mobile phase. A gas chromatographic system with the capillary
column, DB-624 with dimensions of 30 m × 0.53 mm × 3 µm has been utilized for the separation of analytes.
The flow rate was maintained at a mode of consistent flow with 2.0 ml/min. The temperature of the column
was been maintained at 40°C for 11 min, elevated to 240°C with a speed of 30°C per min, and held at 240°C
for 12.33 min. Nitrogen has been utilized as the carrier gas. The temperature of the injection has been kept
at 180°C. The detector temperature has been maintained at 250°C. The gas split ratio was 20:1. The data
sensitivity has been acquired at 20 Hz/ 0.1. The make-up gas flow has been kept constant at 30 ml/min. The
fuel flow has been upheld at 40 ml/min. The oxidizer flow was found to be 400 ml/min. The run time was 30
min. By the ICH guidelines, the analytical procedure was validated for ethosuximide. The approach has been
discovered to be linear, exhibiting a coefficient of correlation of 0.99 and a y-intercept value of 0.74.