Diazepam

In the present study, effects of increasing doses of sesamol (25, 50 and 100mg/kg) on anxiety were investigated in adult Swiss albino mice using elevated plus-maze, light/dark box, open field and hole board  tests as animal models compared with the effects of the standard anxiolytic diazepam (1.0 mg/kg) and vehicle, which were administered intraperitoneally. Sesamol was found to significantly increase the time spent and number of entries in open arm when compared to closed arm in elevated plus maze apparatus. In light/ dark box model, time spent in light box and number of crossings between compartments increased significantly. In open field test, significant increase in number of rearing, assisted rearing and number of square crossed were observed. It was also observed that sesamol significantly increased the number of head dips in hole board test. These results infer that, sesamol having anxiolytic activity in a dose-dependent manner. 

  A simple, specific, accurate and precise reverse phase high performance liquid chromatographic method was developed for simultaneous estimation of diazepam and propranolol hydrochloride in pharmaceutical tablet formulation. The separation was achieved on Phenomenex C18 column (250 mm i.d., 4.6 mm, 5 µm particle size) using methanol: acetonitrile: water (50 : 25 : 25, v/v/v, pH adjusted to 2.8 ± 0.05 with ortho- phosphoric acid) as the mobile phase at a flow rate of 1.0 ml min-1. The quantification was achieved with PDA detector at 235 nm. The injection volume was 20 µl. The retention times of diazepam and propranolol hydrochloride were 5.38 ± 0.29 min and 3.80 ± 0.15 min, respectively. The method was validated for linearity, precision, specificity, robustness and recovery according to the ICH guidelines. The linearity was obtained in the concentration range of 0.1-5.0 µg/ml for both drugs with mean recovery of 100.3 ± 0.47 and 100.2 ± 0.78 % for diazepam and propranolol hydrochloride, respectively. The limit of detection and quantification for diazepam were 0.015 and 0.050 µg/ml, respectively and for propranolol hydrochloride were 0.014 and 0.045 µg/ml, respectively. The method was found to be simple and highly sensitive and can be useful in the routine quality control of diazepam and propranolol hydrochloride in bulk manufacturing and pharmaceutical dosage forms.   Key words: Diazepam, propranolol hydrochloride, RP-HPLC, validation, simultaneous, tablet