Cefalexin Tablets

Cephalosporin antibacterial.

Cefalexin Tablets contain Cefalexin Monohydrate.

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

92.5 to 110.0% of the stated amount.

Remove any coating. Shake a quantity of the powdered tablet cores containing the equivalent of 0.5 g of anhydrous cefalexin with 1 mL of water and 1.4 mL of 1m hydrochloric acid, add 0.1 g of activated charcoal, shake, filter and wash the filter with 1 mL of water. Add slowly to the filtrate a saturated solution of sodium acetate until precipitation occurs. Add 5 mL of methanol, filter and wash the precipitate with two 1 mL quantities of methanol. The residue, after drying at a pressure not exceeding 0.7 kPa, complies with the following tests.

A. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of cefalexin (RS 049).

B. Complies with test B described under Cefalexin Capsules but preparing solution (1) in the following manner. Shake 0.2 g with 25 mL of a mixture of equal volumes of methanol and 0.067m mixed phosphate buffer pH 7.0, dilute to 50 mL with the same solvent mixture, filter and use the filtrate.

C. Mix 20 mg with 0.25 mL of a 1% v/v solution of glacial acetic acid and add 0.1 mL of a 1% w/v solution of copper(ii) sulfate and 0.1 mL of 2m sodium hydroxide. An olive-green colour is produced.

Maximum time, 30 minutes, Appendix XII A1.

Comply with the test described under Cefalexin Capsules but using the following solutions. For solution (1) shake a quantity of the powdered tablets containing the equivalent of 0.25 g of anhydrous cefalexin with 10 mL of 2m hydrochloric acid, filter and use the filtrate. For solution (2) dilute 1 volume of solution (1) to 100 volumes with 2m hydrochloric acid. Solution (3) contains 0.025% w/v of 7-aminodesacetoxycephalosporanic acid BPCRS in 2m hydrochloric acid. Solution (4) contains 0.025% w/v of dl-phenylglycine in 2m hydrochloric acid. Solution (5) contains 2.5% w/v of cefalexin BPCRS and 0.025% w/v of each of 7-aminodesacetoxycephalosporanic acid BPCRS and dl-phenylglycine in 2m hydrochloric acid.

Weigh and powder 20 tablets. Carry out the Assay described under Cefalexin Capsules but using as solution (1) a solution prepared in the following manner. Shake a quantity of the powdered tablets containing the equivalent of 0.25 g of anhydrous cefalexin with 100 mL of water for 30 minutes, add sufficient water to produce 250 mL, filter and dilute 25 mL of the filtrate to 50 mL with water.

Cefalexin Tablets should be stored at a temperature not exceeding 30°.

The quantity of active ingredient is stated in terms of the equivalent amount of anhydrous cefalexin.