A: Transfer a portion of finely powdered Tablets, equivalent to about 10 mg of phytonadione, to a 1000-mL volumetric flask, add 750 mL of dehydrated alcohol, and shake vigorously. Dilute with dehydrated alcohol to volume, mix, and filter: the UV absorption spectrum of the filtrate exhibits maxima and minima at the same wavelengths as that of a 1 in 100,000 solution of USP Phytonadione RS in dehydrated alcohol concomitantly measured.

B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

Mobile phase— Prepare a suitable filtered and degassed mixture of dehydrated alcohol and water (95:5).

Standard preparation— Prepare a solution of USP Phytonadione RS in dehydrated alcohol having a known concentration of about 0.10 mg per mL.

Assay preparation— Weigh and finely powder not less than 20 Tablets. Transfer a portion of the powdered Tablets, equivalent to about 5 mg of phytonadione, to a 50-mL volumetric flask, add 20 mL of dehydrated alcohol, and shake by mechanical means for 15 minutes. Dilute with dehydrated alcohol to volume, mix, and filter.

Chromatographic system (see Chromatography 621)—The liquid chromatograph is equipped with a 254-nm detector and a 4-mm × 30-cm column that contains packing L1. The flow rate is about 1.5 mL per minute. Chromatograph three replicate injections of the Standard preparation, and record the peak responses as directed for Procedure: the column efficiency determined from the analyte peak is not less than 915 theoretical plates, the relative standard deviation is not more than 2.0%, and the tailing factor is not more than 2.0.

Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the response for the major peak. Calculate the quantity, in mg, of C31H46O2, in the portion of Tablets taken by the formula: in which C is the concentration, in mg per mL, of USP Phytonadione RS in the Standard preparation, and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.