Test solution: 10mg per mL,in dioxane.

Mobile phase— Prepare a suitable degassed solution of 3volumes of acetonitrile in 2volumes of water,such that the retention time of beclomethasone dipropionate is approximately 6minutes and that of testosterone propionate is approximately 10minutes.

Internal standard solution— Dissolve a suitable quantity of USP Testosterone Propionate RS,accurately weighed,in methanol to obtain a solution having a concentration of about 1.2mg per mL.

Standard preparation— Dissolve a suitable quantity of USP Beclomethasone Dipropionate RS,accurately weighed,in methanol to obtain a solution having a concentration of about 1.4mg per mL.Transfer 4.0mLof this solution to a suitable vial,and add 4.0mLof Internal standard solutionto obtain a solution having a known concentration of about 0.7mg per mLwith respect to the Reference Standard and 0.6mg per mLwith respect to the internal standard.

Assay preparation— Weigh accurately about 70mg of Beclomethasone Dipropionate,transfer to a 50-mLvolumetric flask,dilute with methanol to volume,and mix.Transfer 4.0mLof this solution to a suitable vial,and add 4.0mLof Internal standard solution.

Procedure— Separately inject equal volumes (between 5µLand 25µL)of the Assay preparationand the Standard preparationinto a high-performance liquid chromatograph (see Chromatography á621ñ)operated at room temperature,adjusting the specimen size and other operating parameters such that the peak obtained with the internal standard in the Standard preparationis about 0.6to 0.9full-scale.Typically,the apparatus is fitted with a 4-mm ×30-cm column that contains packing L1and is equipped with an UVdetector capable of monitoring absorption at 254nm,a suitable recorder,and a pump capable of operating at a column pressure of up to 3500psi.In a suitable chromatogram,the coefficient of variation for five replicate injections of the Standard preparationis not more than 3.0%.Calculate the quantity,in mg,of C28H37ClO7in the portion of Beclomethasone Dipropionate taken by the formula: in which Cis the concentration,in mg per mL,of USP Beclomethasone Dipropionate RSin the Standard preparation;and RUand RSare the peak height ratios of beclomethasone dipropionate to the internal standard obtained from the Assay preparationand the Standard preparation,respectively.