Nystatin Tablets

Action and use

Antifungal.

Definition

Nystatin Tablets contain Nystatin. They are coated.

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

Identification

Extract a quantity of the powdered tablets containing 300,000 IU with a mixture of 5 mL of glacial acetic acid and 50 mL of methanol, add sufficient methanol to produce 100 mL and filter. Dilute 1 mL of the filtrate to 100 mL with methanol. The light absorption of the resulting solution, Appendix II B, in the range 250 to 350 nm exhibits three maxima, at 291, 305 and 319 nm. The ratios of the absorbances at the maxima at 291 nm and 319 nm to the absorbance at the maximum at 305 nm are 0.61 to 0.73 and 0.83 to 0.96, respectively. Use in the reference cell a solution prepared in exactly the same manner but omitting the preparation being examined.

Tests

Disintegration

Maximum time, 30 minutes, Appendix XII A1, but using a 0.6% v/v solution of hydrochloric acid in place of water. If the tablets fail to disintegrate, wash them rapidly by immersion in water and continue the test using phosphate buffer pH 6.8; the tablets then disintegrate within a further 30 minutes.

Loss on drying

When dried at 60° at a pressure not exceeding 0.7 kPa for 3 hours, the powdered tablets lose not more than 5.0% of their weight. Use 1 g.

Assay

Carry out the following procedure protected from light. Weigh and powder 20 tablets. Shake a quantity of the powder containing 200,000 IU with 50 mL of dimethylformamide for 1 hour. Centrifuge, dilute 10 mL of the clear, supernatant liquid to 200 mL with a solution containing 9.56% w/v of potassium dihydrogen orthophosphate and 11.5% v/v of 1m potassium hydroxide and carry out the microbiological assay of antibiotics, Appendix XIV A. The precision of the assay is such that the fiducial limits of error are not less than 95% and not more than 105% of the estimated potency. The upper fiducial limit of error is not less than 97.0% and the lower fiducial limit of error is not more than 110.0% of the stated number of IU.

Labelling

The quantity of active ingredient is stated as the number of IU (Units).