Medium: 0.01Nhydrochloric acid;900mL.

Apparatus 1: 100rpm.

Time: 30minutes.

Procedure— Determine the amount of C11H12Cl2N2O5dissolved by employing UVabsorption at the wavelength of maximum absorbance at about 278nm on filtered portions of the solution under test,suitably diluted with Dissolution Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Chloramphenicol RSin the same Medium.

Tolerances— Not less than 85%(Q)of the labeled amount of C11H12Cl2N2O5is dissolved in 30minutes.

Mobile phase and Chromatographic system—Proceed as directed in the Assayunder Chloramphenicol.

Standard preparation— Transfer about 25mg of USP Chloramphenicol RS,accurately weighed,to a 200-mLvolumetric flask,add 10mLof water,and heat on a steam bath until completely dissolved.Cool to room temperature,dilute with Mobile phaseto 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— Transfer an accurately counted number of Chloramphenicol Capsules,equivalent to about 2500mg of chloramphenicol,to a 1000-mLvolumetric flask,add 100mLof water,and heat on a steam bath until the Capsules have disintegrated.Add 300mLof water,and heat on a steam bath for 20minutes,with occasional mixing.Cool to room temperature,dilute with water to volume,and mix.Transfer 5.0mLof the resulting solution to a 100-mLvolumetric flask,dilute with Mobile phaseto 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 Assay preparation.

Procedure— Proceed as directed for Procedurein the Assayunder Chloramphenicol.Calculate the quantity,in mg,of C11H12Cl2N2O5in each Capsule taken by the formula: in whichNis the number of Capsules taken,and the other terms are as defined therein.