Aspirin Tablets

Acetylsalicylic Acid Tablets

Salicylate; non-selective cyclo-oxygenase inhibitor; antipyretic; analgesic; anti-inflammatory.

Aspirin Tablets contain Aspirin.

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

95.0 to 105.0% of the stated amount.

Boil 0.5 g of the powdered tablets for 2 to 3 minutes with 10 mL of 5m sodium hydroxide, cool and add an excess of 1m sulfuric acid; a crystalline precipitate is produced. To a solution of the precipitate in water add iron(iii) chloride solution R1; a deep violet colour is produced.

Shake a quantity of the powdered tablets containing 0.20 g of Aspirin with 4 mL of ethanol (96%) and dilute to 100 mL with water at a temperature not exceeding 10°. Filter immediately, transfer 50 mL of the filtrate to a Nessler cylinder, add 1 mL of freshly prepared ammonium iron(iii) sulfate solution R1, mix and allow to stand for 1 minute. Any violet colour produced is not more intense than that obtained by adding 1 mL of freshly prepared ammonium iron(iii) sulfate solution R1 to a mixture of 3 mL of a freshly prepared 0.10% w/v solution of salicylic acid, 2 mL of ethanol (96%) and sufficient water to produce 50 mL contained in a second Nessler cylinder (3.0%).

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

(a) Use Apparatus 1, rotating the basket at 50 revolutions per minute.

(b) Use 500 mL of a pH 4.5 buffer prepared by mixing 29.9 g of sodium acetate and 16.6 mL of glacial acetic acid with sufficient water to produce 10 litres at a temperature of 37°, as the medium.

(1) After 45 minutes withdraw a sample of the medium and measure the absorbance of the filtered sample, suitably diluted with the dissolution medium if necessary, at the maximum at 265 nm, Appendix II B using dissolution medium in the reference cell.

(2) Measure the absorbance of a suitable solution of aspirin BPCRS using dissolution medium in the reference cell.

Calculate the total content of aspirin, C₉H₈O₄, in the medium from the absorbances obtained and using the declared content of C₉H₈O₄ in aspirin BPCRS.

Weigh and powder 20 tablets. To a quantity of the powder containing 0.5 g of Aspirin add 30 mL of 0.5m sodium hydroxide VS, boil gently for 10 minutes and titrate the excess of alkali with 0.5m hydrochloric acid VS using phenol red solution as indicator. Repeat the operation without the substance being examined. The difference between the titrations represents the amount of sodium hydroxide required. Each mL of 0.5m sodium hydroxide VS is equivalent to 45.04 mg of C₉H₈O₄.

The label states that the tablets contain Aspirin, unless this word appears in the name of the tablets. This requirement does not apply in countries where exclusive proprietary rights in the name Aspirin are claimed.