A: Infrared Absorption 197K.

B: A solution (1 in 500) responds to the tests for Chloride 191.

Buffer solution, Mobile phase, and Chromatographic system— Prepare as directed under Assay.

Test preparation— Use the Assay preparation.

Procedure— Inject a volume (about 20 µL) of the Test preparation into the chromatograph, record the chromatogram obtained for a period of not less than twice the retention time of cyclopentolate, and measure the peak responses. Calculate the percentage of each peak, other than the solvent peak and the cyclopentolate peak, in the specimen of Cyclopentolate Hydrochloride taken by the same formula: in which ri is the response of each peak and rt is the sum of the responses of all of the peaks, excluding that of the solvent peak: not more than 1.0% individual impurity and not more than 2.0% total impurities are found.

Buffer solution— Dissolve 660 mg of dibasic ammonium phosphate in 1000 mL of water. Adjust with phosphoric acid to a pH of 3.0 ± 0.1, and mix.

Mobile phase— Prepare a suitable filtered and degassed mixture of acetonitrile and Buffer solution (7:3). Make adjustments if necessary (see System Suitability under Chromatography 621).

Standard preparation— Dissolve an accurately weighed quantity of USP Cyclopentolate Hydrochloride RS in water, dilute quantitatively, and stepwise if necessary, with water, and mix to obtain a solution having a known concentration of about 0.1 mg per mL.

Assay preparation— Transfer about 100 mg of Cyclopentolate Hydrochloride, accurately weighed, to a 100-mL volumetric flask, dilute with water to volume, and mix. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, dilute with water to volume, and mix.

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 220-nm detector and a 4.6-mm × 15-cm column that contains packing L15. The flow rate is about 2 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the column efficiency determined from the analyte peak is not less than 3000 theoretical plates, the tailing factor for the analyte peak is not more than 2.0, and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C17H25NO3·HCl in the portion of Cyclopentolate Hydrochloride taken by the formula: in which C is the concentration, in mg per mL, of USP Cyclopentolate Hydrochloride RS in the Standard preparation; and rU and rS are the cyclopentolate peak responses obtained from the Assay preparation and the Standard preparation, respectively.