Tolazamide Tablets

General Notices

Action and use

Inhibition of ATP-dependent potassium channels (sulfonylurea); treatment of diabetes mellitus.

Definition

Tolazamide Tablets contain Tolazamide.

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

Content of tolazamide, C14H21N3O3S

95.0 to 105.0% of the stated amount.

Identification

Triturate a quantity of the powdered tablets containing 0.25 g of Tolazamide with 50 mL of acetone and filter. Evaporate the filtrate to dryness and dry at 60° at a pressure of 2 kPa for 3 hours. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of tolazamide (RS 342).

Tests

Related substances

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

(1) Shake a quantity of the powdered tablets containing 0.20 g of Tolazamide with 10 mL of acetone and filter.
(2) 0.010% w/v of toluene-p-sulfonamide in acetone.
chromatographic conditions
(a) Use as the coating silica gel G.
(b) Use the mobile phase as described below.
(c) Apply 10 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry it in a current of cold air, heat at 110° for 10 minutes, place the hot plate in a tank of chlorine gas, prepared by the addition of hydrochloric acid to a 5% w/v solution of potassium permanganate contained in a beaker placed in the tank and allow to stand for 2 minutes. Dry it in a current of cold air until an area of the plate below the line of application gives at most a very faint blue colour with a 0.5% w/v solution of potassium iodide in starch mucilage; avoid prolonged exposure to cold air. Spray the plate with a 0.5% w/v solution of potassium iodide in starch mucilage.
mobile phase

23 volumes of 13.5m ammonia, 60 volumes of cyclohexane, 100 volumes of methanol and 200 volumes of chloroform.

limits

Any secondary spot in the chromatogram obtained with solution (1) is not more intense that the spot in the chromatogram obtained with solution (2) (0.5%).

Assay

Weigh and powder 20 tablets. Shake a quantity of the powdered tablets containing 0.5 g of Tolazamide with 50 mL of chloroform, filter, wash the residue with chloroform and evaporate the combined filtrate and washings to dryness. Dissolve the residue in 20 mL of butan-2-one with the aid of gentle heat. Allow to cool, add 30 mL of ethanol (96%) and titrate the resulting solution with 0.1m sodium hydroxide VS using phenolphthalein solution R1 as indicator. Each mL of 0.1m sodium hydroxide VS is equivalent to 31.14 mg of C14H21N3O3S.