Standard solution— Transfer 2.0 mL of 0.100 N iodine VS to a 500-mL volumetric flask, dilute with water to volume, and mix.

Procedure— Visually examine a portion of the Inhalation Solution (Test solution) in a suitable clear glass test tube against a white background: it is not pinkish and it contains no precipitate. If any yellow color is observed in the Test solution, concomitantly determine the absorbances of the Test solution and the Standard solution in 1-cm cells with a suitable spectrophotometer set at 460 nm: the absorbance of the Test solution does not exceed that of the Standard solution.

Standard preparation— Prepare as directed in the Assay under Isoproterenol Hydrochloride.

Assay preparation— Transfer an accurately measured volume of Inhalation Solution, equivalent to about 25 mg of isoproterenol hydrochloride, to a 100-mL volumetric flask, dilute with 0.17 N acetic acid solution to volume, and mix.

Chromatographic system— Proceed as directed in the Assay under Isoproterenol Hydrochloride.

Procedure— Proceed as directed for Procedure in the Assay under Isoproterenol Hydrochloride. Calculate the quantity, in mg, of C11H17NO3·HCl in each mL of the Inhalation Solution taken by the formula: in which V is the volume, in mL, of Inhalation Solution taken; and C, hU, and hS are as defined therein.