Estimation of Diazepam (2/5/10mg) tablets by HPLC method

1.0 OBJECTIVE

To provide the procedure for the determination of Diazepam (2/5/10mg) tablets by HPLC method

2.0 SCOPE

This procedure is Applicable to the determination of Diazepam (2/5/10mg) tablets by HPLC method

3.0 RESPONSIBILITY

3.1 QC-Chemist

4.0 ACCOUNTABILITY

4.1 Executive – Quality control

4.2 Head – Quality control

5.0 PROCEDURE

Diazepam (DZ) is 7-chloro-1, 3-dihydro-1-methyl-5-phenyl-2H-1, 4-benzodiazepin-2-one (C16 H13ClN2O), mol. wt. 284.74.

The drug diazepam has been marketed for the treatment of CNS disturbance disorder for more than 20 years, and it remains one of the leading products in this therapeutic area.

Diazepam is a benzodiazepine calcium-channel blocker with peripheral and coronary vasodilatator properties. It is administered orally in the treatment of tranquilizer, anticonvulsant, antidepressant and hypnotic, and may be given intravenously in the treatment of preanaesthetic medication .

It is a yellowish white color crystalline powder. It is freely soluble in methanol, ethanol and chloroform but it is sparingly soluble in water.

In reversed phase liquid chromatography the stationary phase is non polar and the mobile phase is polar. Retention is the result of interaction of the non polar components of the solutes and the nonpolar stationary phase so that nonpolar compounds are retained more strongly, while the polar elute first.

Diazepam

5.1 MATERIALS AND METHOD

An HPLC instrument of LC-10AT VP series (Shimadzu Corporation, Switzerland) consisting of a UV-Visible detector, manual injector with 20µl loop and Hypersil ODS C18 column (250 mm X 4.6 mm i.d., 5µm particle sizes) was used. HPLC-grade methanol and water(Qualigens) and Diazepam (DZ) 10 mg tablets.

5.2 Chromatographic conditions

Chromatography was performed on Hypersil C18 reversed phase column (250 mm x 4.6 mm i.d., 5µl) base deactivated silyl bonded amorphous silica. The mobile phase was methanol and water, 70:30 (v/v). Flow-rate was 1ml/min). The column was kept at 25.0 ± 0.1 _C during the analysis; the detection wavelength was 284nm and the injection volume was 20µl .

5.3 Mobile Phase:

30 Volumes of water and 70 Volumes of methanol

5.4 Standard Preparation:

Weigh accurately about 100mg of Diazepam working standards in a 100ml volumetric flask and dissolve with 60ml of methanol and dilute to 100 ml with mobile Phase.

Dilute 1ml of the above solution in to 100 ml with dilute with mobile phase upto the mark.

5.5 Sample Preparation:

Weight powder twenty tablets and take the powder equivalent to 100mg Diazepam was accurately weighed, dissolved in 60ml of methanol and dilute to 100ml with mobile Phase, filtered through Whatmann filter paper No: 41.

Dilute 1ml of the above solution in to 100 ml with dilute with mobile phase upto the mark..

5.6 Retention Time: