Oxprenolol Tablets

General Notices

Action and use

Beta-adrenoceptor antagonist.

Definition

Oxprenolol Tablets contain Oxprenolol Hydrochloride. They are coated.

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

Content of oxprenolol hydrochloride, C₁₅H₂₃NO₃,HCl

95.0 to 105.0% of the stated amount.

Identification

A. To a quantity of the powdered tablets containing 50 mg of Oxprenolol Hydrochloride add 10 mL of water and 2 mL of 1.25m sodium hydroxide, extract with 10 mL of chloroform and reserve the aqueous layer for test B. Dry the chloroform extract over anhydrous sodium sulfate, filter and evaporate the filtrate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of oxprenolol (RS 255).

B. The aqueous layer obtained in test A yields reaction A characteristic of chlorides, Appendix VI.

Related substances

Carry out the method for thin-layer chromatography, Appendix III A, using silica gel G as the coating substance and a mixture of 2 volumes of 13.5m ammonia, 12 volumes of methanol and 88 volumes of chloroform as the mobile phase, but allowing the solvent front to ascend 13 cm above the line of application. Apply separately to the plate 2 µL of each of the following solutions. For solution (1) shake a quantity of the powdered tablets containing 0.25 g of Oxprenolol Hydrochloride with 5 mL of water, centrifuge and use the supernatant liquid. For solution (2) dilute 1 volume of solution (1) to 200 volumes with water. Allow the spots to dry in air for 15 minutes before development. After removal of the plate, dry it in a current of warm air for 10 minutes, allow to cool, spray with anisaldehyde solution, heat at 100° to 105° for 5 to 10 minutes and examine in daylight. Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) (0.5%).

Assay

Weigh and powder 20 tablets. Mix a quantity of the powder containing 20 mg of Oxprenolol Hydrochloride with 25 mL of 0.1m hydrochloric acid and add sufficient water to produce 250 mL. Mix with the aid of ultrasound for 5 minutes, shake for 15 minutes and filter. Measure the absorbance of the solution at the maximum at 273 nm, Appendix II B. Calculate the content of C₁₅H₂₃NO₃,HCl taking 74.5 as the value of A(1%, 1 cm) at the maximum at 273 nm.