Packaging and storage— Preserve in tight, light-resistant containers.

Labeling— Label it to indicate that it is intended for veterinary use only.

USP Reference standards 11— USP Chlortetracycline Hydrochloride RS.

Loss on drying 731— Dry about 100 mg, accurately weighed, in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours: it loses not more than 2.0% of its weight.

Residual solvents 467: meets the requirements.

Assay for chlortetracycline hydrochloride— Proceed as directed for chlortetracycline under Antibiotics—Microbial Assays 81, using an accurately weighed quantity of Powder, equivalent to about 100 mg of chlortetracycline hydrochloride, dissolved in an accurately measured volume of 0.01 N hydrochloric acid to obtain a stock solution having a convenient concentration. Dilute an accurately measured volume of this stock solution quantitatively and stepwise with water to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.

Assay for sulfamethazine— Proceed as directed under Nitrite Titration 451, using an accurately weighed quantity of Powder, equivalent to about 500 mg of sulfamethazine. Each mL of 0.1 M sodium nitrite is equivalent to 27.83 mg of sulfamethazine (C12H14N4O2S).

Expert Committee : (VET05) Veterinary Drugs 05

USP29–NF24 Page 497

Phone Number : 1-301-816-8178