Dissolution á711ñ—
pH4.0buffer—
Transfer 10.94g of anhydrous dibasic sodium phosphate and 12.92g of citric acid monohydrate to a 1-liter volumetric flask,dissolve in water,dilute with water to volume,and mix.
Medium:
pH4.0buffer;900mL.
Apparatus 2:
50rpm.
Time:
45minutes.
Procedure—
Determine the amount of nafcillin (C
21H
22N
2O
5S)dissolved from UVabsorbances,at the wavelength of maximum absorbance at about 280nm of filtered portions of the solution under test,suitably diluted with
Medium,if necessary,in comparison with a Standard solution having a known concentration of
USP Nafcillin Sodium RSin the same medium.
Tolerances—
Not less than 75%(Q)of the labeled amount of nafcillin (C21H22N2O5S)is dissolved in 45minutes.
Assay—
Proceed as directed under
Antibiotics—Microbial Assays á81ñ,using not less than 5Tablets blended for 4±1minutes in a high-speed glass blender jar containing an accurately measured volume of
Buffer No.1.Dilute an accurately measured volume of this stock solution quantitatively with
Buffer No.1to obtain a
Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.