Chloramphenicol, Polymyxin B Sulfate, and Hydrocortisone Acetate Ophthalmic Ointment
» Chloramphenicol, Polymyxin B Sulfate, and Hydrocortisone Acetate Ophthalmic Ointment contains not less than 90.0 percent and not more than 120.0 percent of the labeled amount of chloramphenicol (C11H12Cl2N2O5), not less than 90.0 percent and not more than 125.0 percent of the labeled amount of polymyxin B, and not less than 90.0 percent and not more than 115.0 percent of the labeled amount of hydrocortisone acetate (C23H32O6).
Packaging and storage—
Preserve in collapsible ophthalmic ointment tubes.
USP Reference standards 
11
—
11—
USP Chloramphenicol RS 
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USP Polymyxin B Sulfate RS
USP Hydrocortisone Acetate RS
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Identification—
The retention times of the major peaks in the chromatogram of the Assay preparation correspond to those in the chromatogram of the Standard preparation as obtained in the Assay for chloramphenicol and hydrocortisone acetate.
Sterility 71:
meets the requirements.
71:
meets the requirements.
Minimum fill 755:
meets the requirements.
755:
meets the requirements.
Metal particles—
It meets the requirements under Metal Particles in Ophthalmic Ointments 751.
751.
Assay for polymyxin—
Proceed with Ophthalmic Ointment as directed for polymyxin under Antibiotics—Microbial Assays 81, using an accurately weighed portion of Ophthalmic Ointment, equivalent to about 5000 Polymyxin B Units, shaken in a separator containing about 50 mL of ether and extracted with four 20-mL portions of Buffer No. 6. Combine the aqueous extracts in a 100-mL volumetric flask, dilute, if necessary, with Buffer No. 6 to volume, and mix. Dilute an accurately measured portion of the resulting solution quantitatively with Buffer No. 6 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.
81, using an accurately weighed portion of Ophthalmic Ointment, equivalent to about 5000 Polymyxin B Units, shaken in a separator containing about 50 mL of ether and extracted with four 20-mL portions of Buffer No. 6. Combine the aqueous extracts in a 100-mL volumetric flask, dilute, if necessary, with Buffer No. 6 to volume, and mix. Dilute an accurately measured portion of the resulting solution quantitatively with Buffer No. 6 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.
Assay for chloramphenicol and hydrocortisone acetate—
Mobile phase
and Chromatographic system—Proceed as directed in the Assay under Chloramphenicol.
Standard preparation—
Transfer about 25 mg of USP Chloramphenicol RS and 25J mg of USP Hydrocortisone Acetate RS, both accurately weighed, J being the ratio of the labeled amount, in mg, of hydrocortisone acetate to the labeled amount, in mg, of chloramphenicol per g of Ophthalmic Ointment, to a 100-mL volumetric flask, dissolve in methanol, dilute with methanol to volume, and mix. Transfer 10.0 mL of the resulting solution to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix. Filter a portion of this solution through a 0.5-µm or finer porosity filter, and use the clear filtrate as the Standard preparation.
Assay preparation—
Using Ophthalmic Ointment, proceed as directed for Assay preparation in the Assay under Chloramphenicol Ophthalmic Ointment.
Procedure—
Proceed as directed for Procedure in the Assay under Chloramphenicol. Calculate the quantity, in mg, of chloramphenicol (C11H12Cl2N2O5) in the portion of Ophthalmic Ointment taken by the formula:
0.25C(rU / rS)
in which the terms are as defined therein. Calculate the quantity, in mg, of hydrocortisone acetate (C23H32O6) in the portion of Ophthalmic Ointment taken by the formula:
250C(rU / rS)
in which C is the concentration, in mg per mL, of USP Hydrocortisone Acetate RS in the Standard preparation, and the other terms are as defined therein.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Ahalya Wise, M.S.
Senior Scientific Liaison 1-301-816-8161 |
(SM12010) Monographs - Small Molecules 1 |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
|
| 71 |
Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison 1-301-816-8339 |
(GCM2010) General Chapters - Microbiology |
USP35–NF30 Page 2611