Diltiazem Hydrochloride Oral Suspension
» Diltiazem Hydrochloride Oral Suspension contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of diltiazem hydrochloride (C22H26N2O4S·HCl). Prepare Diltiazem Hydrochloride Oral Suspension 12 mg per mL as follows (see Pharmaceutical Compounding—Nonsterile Preparations 795. See also Diltiazem Hydrochloride Oral Solution):
Diltiazem Hydrochloride 1.2 g
Vehicle: a mixture of Vehicle for Oral Solution (regular or sugar-free), NF, and Vehicle for Oral Suspension, NF  
(1:1), a sufficient quantity to make 100 mL
If using Tablets, comminute the Tablets to a fine powder in a suitable mortar, or add Diltiazem Hydrochloride powder to the mortar. Add approximately 10 mL of the Vehicle, and mix to a uniform paste. Add the Vehicle to the mortar in small portions almost to volume, and mix thoroughly after each addition. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add enough Vehicle to bring to final volume.
Packaging and storage— Preserve in tight, light-resistant containers. Store at controlled room temperature, or in a cold place.
Labeling— Label it to state that it is to be well shaken, and to state the beyond-use date.
USP Reference standards 11
USP Diltiazem Hydrochloride RS Click to View Structure
pH 791: between 3.7 and 4.7.
Beyond-use date: 60 days after the day on which it was compounded.
Buffer solution— Dissolve 1.16 g of d-10-camphorsulfonic acid in 1000 mL of 0.1 M sodium acetate, adjust this solution by the addition of 0.1 N sodium hydroxide to a pH of 6.2, and mix.
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile, methanol, and Buffer solution (2:1:1). Make adjustments if necessary (see System suitability under Chromatography 621).
Standard preparation— Dissolve USP Diltiazem Hydrochloride RS in Mobile phase to obtain a solution having a known concentration of 120 µg per mL.
Assay preparation— Agitate the container of Oral Suspension for 30 minutes on a rotating mixer, remove a 5-mL sample, and store in a clear glass vial at –70 until analyzed. At the time of analysis, remove the sample from the freezer, allow it to reach room temperature, and mix with a vortex mixer for 30 seconds. Pipet 1.0 mL of the sample solution into a 100-mL volumetric flask, and dilute with Mobile phase to volume.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 240-nm detector and a 4.6-mm × 25-cm analytical column that contains 5-µm packing L1. The flow rate is about 1.5 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the retention time is about 9.6 minutes; and the relative standard deviation for replicate injections is not more than 1.3%.
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 the major peaks. Calculate the quantity, in mg, of diltiazem hydrochloride (C22H26N2O4S·HCl) in the volume of Oral Suspension taken by the formula:
100(C/V)(rU / rS)
in which C is the concentration, in µg per mL, of USP Diltiazem Hydrochloride RS in the Standard preparation; V is the volume, in mL, of Oral Suspension taken; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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Monograph Jeanne H. Sun
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