Packaging and storage—
Preserve in tight,light-resistant containers.The containers or individual cartons are sealed and tamper-proof so that sterility is assured at time of first use.
Assay for neomycin—
Proceed as directed under
Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of Otic Solution diluted quantitatively and stepwise with
Buffer No.3to yield a
Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard (1.0µg of neomycin per mL).
Assay for polymyxin B—
Proceed as directed under
Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of Otic Solution diluted quantitatively and stepwise with
Buffer No.6to yield a
Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard (10Polymyxin B Units per mL).Add to each test dilution of the Standard a quantity of Neomycin Standard,dissolved in
Buffer No.6,to obtain the same concentration of neomycin present in the
Test Dilution.
Assay for hydrocortisone—
Mobile phase
,Standard preparation,and Chromatographic system—Prepare as directed in the Assay for hydrocortisoneunder Neomycin and Polymyxin B Sulfates,Bacitracin Zinc and Hydrocortisone Ophthalmic Ointment.
Assay preparation—
Transfer 3.0mLof Otic Solution to a 200-mLvolumetric flask,dilute with a mixture of methanol and water (1:1)to volume,and mix.
Procedure—
Proceed as directed for
Procedurein the
Assay for hydrocortisoneunder
Neomycin and Polymyxin B Sulfates,Bacitracin Zinc and Hydrocortisone Ophthalmic Ointment.Calculate the quantity,in mg,of C
21H
30O
5in each mLof the Otic Solution taken by the formula:
(66.67C)(rU/rS),
in which
Cis the concentration,in mg per mL,of
USP Hydrocortisone RSin the
Standard preparation,and
rUand
rSare the peak responses obtained from the
Assay preparationand the
Standard preparation,respectively.