Determination of zopiclone in tablets by HPLC and UV-spectrophotometry.

Rapid, simple and accurate chromatographic (HPLC) and spectrophotometric methods for the determination of zopiclone in tablets were elaborated. Acetonitrile was found to be a suitable extraction solvent. The samples were chromatographed on Nova-Pak C18 column and UV detection at 304 nm. The elution was achieved isocratically with a mobile phase of 0.067 M phosphate buffer pH 7.95 - acetonitrile (55:45, v/v). Diazepam was applied as an internal standard. The method was validated for precision, linearity, accuracy and limit of detection. The recovery (mean +/- SD) in HPLC was 99.85 + 0.04% and in the UV-spectrophotometry 100.08 +/- 0.09%.