Medium: water; 500 mL.

Apparatus 2: 50 rpm.

Time: 15 minutes.

Procedure— Place 1 Capsule in each vessel, and allow the Capsule to sink to the bottom of the vessel before starting rotation of the blade. Observe the Capsules, and record the time taken for each capsule shell to rupture.

Tolerances— The requirements are met if all of the Capsules tested rupture in not more than 15 minutes. If 1 or 2 of the Capsules rupture in more than 15 but not more than 30 minutes, repeat the test on 12 additional Capsules. Not more than 2 of the total of 18 Capsules tested rupture in more than 15 but not more than 30 minutes.

Mobile phase— Prepare a filtered and degassed mixture of methanol, water, and tetrahydrofuran (71:24:5), making adjustments, if necessary (see System Suitability under Chromatography 621).

System suitability solution— Mix accurately measured volumes of USP D9-Tetrahydrocannabinol RS and USP D8-Tetrahydrocannabinol RS in dehydrated alcohol to obtain a solution having a known concentration of about 0.5 mg per mL of each component.

Standard preparation— Dissolve an accurately measured volume of USP D9-Tetrahydrocannabinol RS in dehydrated alcohol to obtain a solution having a known concentration of about 0.2 mg per mL.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 228-nm detector, a 4.6- × 30-mm guard column that contains 5-µm packing L1, and a 4.6-mm × 15-cm analytical column that contains 3-µm packing L1. The flow rate is about 1 mL per minute. Chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 1.0 for D9-tetrahydrocannabinol and 1.14 for D8-tetrahydrocannabinol; the resolution, R, between dronabinol and D8-tetrahydrocannabinol is not less than 2.0; and the tailing factor of the D9-tetrahydrocannabinol peak is not more than 2.0. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not greater than 2.0%

Assay preparation— Weigh and mix the contents of not less than 20 Capsules. Transfer an accurately weighed portion of the capsule contents, equivalent to about 20 mg of dronabinol, to a 100-mL volumetric flask, dilute with dehydrated alcohol to volume, and mix.

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 all of the peaks. Calculate the quantity, in mg, of dronabinol (C21H30O2) in the portion of Capsules taken by the formula: in which C is the concentration, in mg per mL, of USP D9-Tetrahydrocannabinol RS in the Standard preparation, and rU and rS are the dronabinol peak responses obtained from the Assay preparation and the Standard preparation, respectively.