First- and Second-Derivative Spectrophotometry for Simultaneous Determination of lorazepam and clonazepam in pharmaceutical formulations

The present study describes employing zero-, 1st -and 2nd-order derivative spectrophotometric methods have been developed for determination of lorazepam (LORA) and clonazepam (CLON) in commercially available tablets. LORA was determined by means of 1st (D1), 2nd (D2) derivative spectrophotometric techniques using zero cross, peak height, and Peak area. D1 used for the determination of CLON by using zero cross and peak height while D2 (zero cross) was used for the determination of CLON. The method was established to be linear in concentration containing different ratios of LORA and CLON range of (20-200 mg/L) and (5-35 mg/L) at wavelength range (250-370 nm), (210-370nm) respectively. The proposed techniques are highly sensitive, precise and accurate and can be used for the reliable quantitation of lorazepam and clonazepam in tablet formulation.