Chlortetracycline Hydrochloride Ointment
» Chlortetracycline Hydrochloride Ointment contains not less than 90.0 percent and not more than 125.0 percent of the labeled amount of C22H23ClN2O8·HCl in a suitable ointment base.
Packaging and storage—
Preserve in collapsible tubes or in well-closed, light-resistant containers.
Minimum fill 
755
:
meets the requirements.
755:
meets the requirements.
Water, Method I 921:
not more than 0.5%, 20 mL of a mixture of toluene and methanol (7:3) being used in place of methanol in the titration vessel.
921:
not more than 0.5%, 20 mL of a mixture of toluene and methanol (7:3) being used in place of methanol in the titration vessel.
Assay—
Proceed as directed under Antibiotics—Microbial Assays 81, using an accurately weighed quantity of Ointment, equivalent to about 30 mg of chlortetracycline hydrochloride, shaken in a separator with about 50 mL of ether, and extracted with four 20-mL portions of 0.01 N hydrochloric acid. Combine the aqueous extracts in a 100-mL volumetric flask, dilute with 0.01 N hydrochloric acid to volume, and mix. Dilute this stock solution quantitatively and stepwise with water to obtain a Test Dilution having a concentration assumed to be equal to the medium dose level of the Standard.
81, using an accurately weighed quantity of Ointment, equivalent to about 30 mg of chlortetracycline hydrochloride, shaken in a separator with about 50 mL of ether, and extracted with four 20-mL portions of 0.01 N hydrochloric acid. Combine the aqueous extracts in a 100-mL volumetric flask, dilute with 0.01 N hydrochloric acid to volume, and mix. Dilute this stock solution quantitatively and stepwise with water to obtain a Test Dilution having a concentration assumed to be equal to the medium dose level of the Standard.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
| Monograph | Ahalya Wise, M.S.
Scientist 1-301-816-8161 |
(MDANT05) Monograph Development-Antibiotics |
| Reference Standards | Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org |
USP32–NF27 Page 1919