Medium: water;900mL.

Apparatus 1: 100rpm.

Time: 30minutes.

Procedure— Determine the amount of dicloxacillin (C19H17Cl2N3O5S)by a suitable validated spectrophotometric analysis of a filtered portion of the solution under test,suitably diluted with Dissolution Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Dicloxacillin Sodium RSin the same Medium.

Tolerances— Not less than 75%(Q)of the labeled amount of C19H17Cl2N3O5Sis dissolved in 30minutes.

Diluent,Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Dicloxacillin Sodium.

Assay preparation— Remove,as completely as possible,the contents of not fewer than 10Capsules,and weigh.Mix,and transfer an accurately weighed portion of the powder,equivalent to about 200mg of dicloxacillin (C19H17Cl2N3O5S),to a 200-mLvolumetric flask,dilute with Diluentto volume,and mix for 10minutes with the aid of a magnetic stirrer.Filter about 25mLof the resulting solution,discarding the first 5mLof the filtrate.Use the clear filtrate as the Assay preparation.[NOTE—Use this Assay preparation promptly,or refrigerate and use on the day prepared.]

Procedure— Proceed as directed for Procedurein the Assayunder Dicloxacillin Sodium.Calculate the quantity,in mg,of dicloxacillin (C19H17Cl2N3O5S)in the portion of Capsule contents taken by the formula: in which the terms are as defined therein.