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Alprazolam
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C17H13ClN4 308.76

4H-[1,2,4]Triazolo[4,3-][1,4]benzodiazepine, 8-chloro-1-methyl-6-phenyl-.
8-Chloro-1-methyl-6-phenyl-4H-s-triazolo[4,3-][1,4]benzodiazepine [28981-97-7].
» Alprazolam contains not less than 98.0 percent and not more than 102.0 percent of C17H13ClN4.
Caution—Care should be taken to prevent inhaling particles of Alprazolam and exposing the skin to it.
Packaging and storage— Preserve in tight containers, and store at controlled room temperature.
Identification—
B: Ultraviolet Absorption 197U—
Solution: 4 µg per mL.
Medium: alcohol.
Absorptivities at 220 nm, calculated on the dried basis, do not differ by more than 3.0%.
Loss on drying 731— Dry it at a pressure of not more than 5 mm of mercury at 60 for 16 hours: it loses not more than 0.5% of its weight.
Residue on ignition 281: not more than 0.5%.
Chromatographic purity—
METHOD A—
Test solution— Prepare a solution of Alprazolam in chloroform containing about 2 mg per mL.
Chromatographic system (see Chromatography 621)— The gas chromatograph is equipped with a flame-ionization detector, and contains a 3-mm × 120-cm glass column packed with 3% phase G6 on support S1AB. The column and injector port are maintained at a temperature of about 240. The detector is maintained at a temperature about 20 to 50 above the column temperature. The carrier gas is helium.
Procedure— [NOTE—Allow about three times the elution time of the major component between successive injections.] Chromatograph about 4 µL of the Test solution, and record the chromatograms. Calculate the total impurities, in percentage, taken by the formula:
(100)(rA + rB + . . . rI) / (rA + rB + . . . rI + r),
where rA, rB, . . . rI are the responses for each peak other than the alprazolam peak present in the Test solution; and r is the response of the alprazolam peak in the Test solution. The total amount of impurities detected is not more than 1.0%.
METHOD B—
Standard solutions— Prepare a 4.0 mg per mL solution of USP Alprazolam RS in chloroform. Separately dilute 1, 3, and 5 mL of this solution to 100 mL with chloroform to obtain 0.1%, 0.3%, and 0.5% Standard solutions, respectively.
Test solution— Prepare a solution in chloroform containing 40 mg per mL.
Procedure— Separately apply 10 µL each of the Test solution and each Standard solution to a thin-layer chromatographic plate (see Chromatography 621) coated with a 0.50-mm layer of chromatographic silica gel mixture, and allow the spots to dry. Develop the chromatogram in a solvent system consisting of a mixture of chloroform, acetone, ethyl acetate, and methanol (50:50:50:5). Allow the solvent front to move about three-fourths of the length of the plate, remove the plate, and allow to dry. Repeat the development process a second time. Examine the plate under short-wavelength UV light and estimate the amount of any spots, other than the principal spot, in the chromatogram of the Test solution: no individual spot is greater in size or intensity than the spot produced by the 0.3% Standard solution, and the sum of any such spots detected is not greater than 1%.
Residual solvents 467: meets the requirements.
(Official January 1, 2007)
Assay—
Mobile phase— Prepare a filtered and degassed mixture of acetonitrile, chloroform, butyl alcohol, water, and glacial acetic acid (850:80:50:20:0.5). Make adjustments if necessary (see System Suitability under Chromatography 621).
Internal standard solution— Dissolve an accurately weighed quantity of triazolam in acetonitrile, and dilute with acetonitrile to obtain a solution having a known concentration of about 0.25 mg per mL.
Standard preparation— Dissolve an accurately weighed quantity of USP Alprazolam RS in Internal standard solution, and dilute with Internal standard solution to obtain a solution having a known concentration of about 0.25 mg per mL. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, dilute with acetonitrile to volume, and mix.
Assay preparation— Transfer about 2.5 mg of Alprazolam, accurately weighed, to a 10-mL volumetric flask, dissolve in and dilute with Internal standard solution to volume, and mix. Transfer an accurately measured quantity, about 5 mL, of this solution to a 50-mL volumetric flask, dilute with acetonitrile to volume, and mix.
Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 30-cm column that contains packing L3. The flow rate is about 2 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the resolution, R, between the internal standard and alprazolam is not less than 2.0; and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure— [NOTE—Use peak areas where peak responses are indicated.] 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 C17H13ClN4 in the portion of Alprazolam taken by the formula:
100C(RU / RS),
in which C is the concentration, in mg per mL, of USP Alprazolam RS in the Standard preparation; and RU and RS are the peak response ratios of the alprazolam peak relative to the internal standard peak obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information— Staff Liaison : Ravi Ravichandran, Ph.D., Senior Scientist
Expert Committee : (MDPP05) Monograph Development-Psychiatrics and Psychoactives
USP29–NF24 Page 77
Pharmacopeial Forum : Volume No. 27(3) Page 2509
Phone Number : 1-301-816-8330