Nystatin and Triamcinolone Acetonide Ointment
» Nystatin and Triamcinolone Acetonide Ointment contains not less than 90.0 percent and not more than 140.0 percent of the labeled amount of USP Nystatin Units and not less than 90.0 percent and not more than 110.0 percent of the labeled amount of triamcinolone acetonide (C24H31FO6).
Packaging and storage— Preserve in tight containers.
USP Reference standards 11
USP Nystatin RS Click to View Structure
USP Triamcinolone Acetonide RS Click to View Structure
Identification— Place 2 g of Ointment in a conical flask, add 5.0 mL of chloroform, and shake for 10 minutes. Add 15 mL of alcohol, and shake for an additional 10 minutes. Filter the solution into a centrifuge tube, and evaporate the filtrate to dryness. Dissolve the residue in alcohol to obtain a solution containing about 250 µg of triamcinolone acetonide per mL. Proceed as directed in the Identification test under Triamcinolone Acetonide Cream, beginning with “Apply 10 µL of this solution”: the specified result is observed.
Minimum fill 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.
Assay for nystatin— Proceed as directed for nystatin under Antibiotics—Microbial Assays 81, blending a suitable, accurately weighed portion of Ointment in a high-speed blender for 3 to 5 minutes with a sufficient, accurately measured volume of dimethylformamide to give a convenient concentration. Dilute an accurately measured volume of the solution so obtained quantitatively with dimethylformamide to obtain a stock solution containing about 400 USP Nystatin Units per mL. Dilute an accurately measured volume of this stock solution quantitatively with Buffer No. 6 to obtain a Test Dilution having a concentration of nystatin assumed to be equal to the median dose level of the Standard.
Assay for triamcinolone acetonide— Proceed with Ointment as directed in the Assay under Triamcinolone Acetonide Cream, except to read “Ointment” in place of “Cream” throughout.
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
USP35–NF30 Page 4096
Pharmacopeial Forum: Volume No. 28(1) Page 138