Neomycin Tablets
Action and use
Aminoglycoside antibacterial.
Definition
Neomycin Tablets contain Neomycin Sulfate.
Identification
20 volumes of chloroform, 40 volumes of 13.5m ammonia and 60 volumes of methanol.
The principal red spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2) and the principal red spot in the chromatogram obtained with solution (3) appears as a single compact spot.
Tests
Neamine
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
A freshly prepared 3.85% w/v solution of ammonium acetate.
Any spot corresponding to neamine in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2).
Neomycin C
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
Mix 97 mL of tetrahydrofuran, 1.0 mL of water and 0.5 mL of glacial acetic acid with sufficient of a 2.0% v/v solution of absolute ethanol in ethanol-free chloroform to produce 250 mL. Pass the mobile phase through the column for several hours before injecting the solutions.
The test is not valid unless:
the chromatogram obtained with solution (2) shows a principal peak due to neomycin B and a major secondary peak due to neomycin C with a retention time relative to neomycin B of about 0.6;
the column efficiency, determined using the peak due to neomycin B in the chromatogram obtained with solution (2), should be not less than 13,000 theoretical plates per metre.
In the chromatogram obtained with solution (1) the area of the peak corresponding to neomycin C is not less than 3% and not more than 15% of the sum of the areas of the peaks corresponding to neomycin B and neomycin C.
Assay
Weigh and powder 20 tablets. Transfer an accurately weighed quantity of the powder containing 15,000 IU to a flask containing 150 mL of sterile phosphate buffer pH 8.0 and add sufficient of the buffer solution to produce 250 mL. Allow to stand, dilute 10 mL of the clear supernatant liquid to 100 mL with the buffer solution and carry out the microbiological assay of antibiotics, Appendix XIV A. The precision of the assay is such that the fiducial limits of error are not less than 95% and not more than 105% of the estimated potency. The upper fiducial limit of error is not less than 97.0% and the lower fiducial limit of error is not more than 110.0% of the stated number of IU.
Storage
Neomycin Tablets should be protected from light and stored at a temperature not exceeding 30°.
Labelling
The quantity of active ingredient is stated in terms of the number of IU (Units).