A: The solution employed for measurement of absorbance in the Assay exhibits maxima at 245 ± 2 nm and 311 ± 2 nm, and the ratio A245 / A311 is between 2.90 and 3.45.

B: A portion of the contents of Capsules responds to Identification test C under Chlordiazepoxide Hydrochloride.

Medium: water; 900 mL.

Apparatus 1: 100 rpm.

Time: 30 minutes.

Procedure— Measure the amount in solution in filtered portions of the Dissolution Medium, suitably diluted, in 1-cm cells at the wavelength of maximum absorbance at about 245 nm, with a suitable spectrophotometer, in comparison with a Standard solution of known concentration of USP Chlordiazepoxide Hydrochloride RS. Remove the contents of 12 Capsules as completely as possible with the aid of a current of air. Dissolve the empty capsule shells in 900 mL of Dissolution Medium. Filter a portion of the solution, and determine the absorbance at the same dilution and in the same manner as for the Capsules, making any necessary modifications.

Tolerances— Not less than 85% (Q) of the labeled amount of C16H14ClN3O·HCl is dissolved in 30 minutes.

Procedure for content uniformity— [NOTE—Use low-actinic glassware in this procedure.] Transfer the contents of 1 Capsule to a 200-mL volumetric flask, dissolve in and dilute with water to volume, and filter, discarding the first 20 mL of the filtrate. Dilute a portion of the filtrate quantitatively and stepwise with 0.1 N hydrochloric acid to obtain a solution having a concentration of about 6 µg of chlordiazepoxide hydrochloride per mL. Dissolve a suitable quantity of USP Chlordiazepoxide Hydrochloride RS, accurately weighed, in 0.1 N hydrochloric acid to obtain a Standard solution having a known concentration of about 6 µg per mL. Concomitantly determine the absorbances of the two solutions in 1-cm cells at the wavelength of maximum absorbance at about 245 nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in mg, of C16H14ClN3O·HCl in the Capsule by the formula: in which T is the labeled quantity, in mg, of chlordiazepoxide hydrochloride in the Capsule; D is the concentration, in µg per mL, of chlordiazepoxide hydrochloride in the test solution, based on the labeled quantity per Capsule and the extent of dilution; C is the concentration, in µg per mL, of USP Chlordiazepoxide Hydrochloride RS in the Standard solution; and AU and AS are the absorbances of the solution from the contents of the Capsule and the Standard solution, respectively.

(Official January 1, 2007)