Oxazepam Tablets

General Notices

Action and use

Benzodiazepine.

Definition

Oxazepam Tablets contain Oxazepam.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of oxazepam, C15H11ClN2O2

90.0 to 110.0% of the stated amount.

Identification

A. Extract a quantity of the powdered tablets containing 20 mg of Oxazepam with 25 mL of chloroform, filter, evaporate to dryness and dry the residue at 60° at a pressure not exceeding 0.7 kPa. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of oxazepam (RS 253).
B. The light absorption, Appendix II B, in the range 210 to 350 nm of the solution obtained in the Assay exhibits two maxima, at 230 nm and 316 nm.

Tests

Dissolution

Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1.

test conditions
(a) Use Apparatus 2, rotating the paddle at 50 revolutions per minute.
(b) Use 900 mL of 0.01m hydrochloric acid, at a temperature of 37°, as the medium.
procedure
(1) After 45 minutes withdraw a sample of the medium and measure the absorbance of a layer of suitable thickness of the filtered sample, suitably diluted with the dissolution medium if necessary, at the maximum at 236 nm, Appendix II B using 0.01m hydrochloric acid in the reference cell.
determination of content

Calculate the total content of oxazepam, C15H11ClN2O2, in the medium taking 1080 as the value of A(1%, 1 cm) at the maximum at 236 nm.

Related substances

Carry out the following procedure protected from light. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.

(1) Shake a quantity of the powdered tablets containing 30 mg of Oxazepam with 6 mL of acetone and centrifuge.
(2) Dilute 1 volume of solution (1) to 100 volumes with acetone.
(3) Dilute 1 volume of solution (1) to 500 volumes with acetone.
(4) 0.10% w/v of each of oxazepam BPCRS and bromazepam EPCRS in acetone.
chromatographic conditions
(a) Use as the coating silica gel F254 (Merck silica gel 60 F254 is suitable). Before use, wash the plate with methanol allowing the solvent front to ascend 17 cm above the line of application.
(b) Use the mobile phase as described below.
(c) Apply 20 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm).
mobile phase

10 volumes of methanol and 100 volumes of dichloromethane.

system suitability

The test is not valid unless the chromatogram obtained with solution (4) shows two clearly separated spots.

limits

In the chromatogram obtained with solution (1):

any secondary spot is not more intense than the spot in the chromatogram obtained with solution (2) (1%),

not more than one such spot is more intense than the spot in the chromatogram obtained with solution (3) (0.2%).

Assay

Weigh and powder 20 tablets. To a quantity of the powder containing 25 mg of Oxazepam add 150 mL of ethanol (96%) and shake for 30 minutes. Add sufficient ethanol (96%) to produce 250 mL, centrifuge, dilute 5 mL of the supernatant liquid to 100 mL with the same solvent and measure the absorbance of the resulting solution at the maximum at 230 nm, Appendix II B. Calculate the content of C15H11ClN2O2 taking 1250 as the value of A(1%, 1 cm) at the maximum at 230 nm.

Storage

Oxazepam Tablets should be protected from light.