Mobile phase and Chromatographic system—Prepare as directed in the Assay under Dipivefrin Hydrochloride.

Standard preparation— Dissolve a suitable quantity of USP Dipivefrin Hydrochloride RS, accurately weighed, in 0.0015 N hydrochloric acid to obtain a solution having a known concentration of about 1 mg per mL.

Assay preparation— Transfer an accurately measured volume of Ophthalmic Solution, equivalent to about 25 mg of dipivefrin hydrochloride, to a 25-mL volumetric flask, dilute with 0.0015 N hydrochloric acid to volume, if necessary, and mix.

Procedure— Proceed as directed in the Assay under Dipivefrin Hydrochloride. Calculate the quantity, in mg, of C19H29NO5·HCl in each mL of the Ophthalmic Solution taken by the formula: in which C is the concentration, in mg per mL, of USP Dipivefrin Hydrochloride RS in the Standard preparation; V is the volume, in mL, of Ophthalmic Solution taken; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.