Cefalexin Oral Suspension

Cephalosporin antibacterial.

Cefalexin Oral Suspension is a suspension of Cefalexin Monohydrate in a suitable flavoured vehicle. It is prepared by dispersing the dry ingredients in the specified volume of Water just before issue for use.

The dry ingredients comply with the requirements for Powders and Granules for Oral Solutions and Oral Suspensions stated under Oral Liquids.

The dry ingredients should be protected from light and stored at a temperature not exceeding 30°.

For the following tests prepare the Oral Suspension as directed on the label. The suspension, examined immediately after preparation unless otherwise indicated, complies with the requirements stated under Oral Liquids and with the following requirements.

When freshly constituted, not more than 120.0% of the stated amount. When stored at the temperature and for the period stated on the label during which the Oral Suspension may be expected to be satisfactory for use, not less than 80.0% of the stated amount.

A. Complies with test B described under Cefalexin Capsules but preparing solution (1) in the following manner. Shake a quantity of the oral suspension containing the equivalent of 0.2 g of anhydrous cefalexin with 70 mL of methanol, filter, evaporate to dryness using a rotary evaporator and dissolve the residue in sufficient 0.5m hydrochloric acid to produce 50 mL.

B. Shake a quantity of the oral suspension containing the equivalent of 0.1 g of anhydrous cefalexin with 70 mL of methanol, filter and evaporate the filtrate to dryness using a rotary evaporator. Dissolve the residue in the minimum volume of a 1% v/v solution of glacial acetic acid, decolourise if necessary by the addition of sufficient activated charcoal, shake and filter. To 0.25 mL of the resulting solution add 0.1 mL of a 1% w/v solution of copper(ii) sulfate and 0.05 mL of 2m sodium hydroxide. An olive-green colour is produced.

Carry out the Assay described under Cefalexin Capsules but using as solution (1) a solution prepared in the following manner. Shake a weighed quantity of the oral suspension 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.

Determine the weight per mL of the oral suspension, Appendix V G, and calculate the content of C₁₆H₁₇N₃O₄S, weight in volume.

Repeat the procedure using a portion of the oral suspension that has been stored at the temperature and for the period stated on the label during which it may be expected to be satisfactory for use.

The Oral Suspension should be stored at the temperature and used within the period stated on the label.

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