Alprazolam
Click to View Image
C17H13ClN4 308.76

4H-[1,2,4]Triazolo[4,3-a][1,4]benzodiazepine,8-chloro-1-methyl-6-phenyl-.
8-Chloro-1-methyl-6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine [28981-97-7].
»Alprazolam contains not less than 98.0percent and not more than 102.0percent 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—
A: Infrared Absorption á197Mñ.
B: Ultraviolet Absorption á197Uñ—
Solution: 4µg per mL.
Medium: alcohol.
Absorptivities at 220nm,calculated on the dried basis,do not differ by more than 3.0%.
Loss on drying á731ñ— Dry it at a pressure of not more than 5mm of mercury at 60for 16hours:it loses not more than 0.5%of its weight.
Residue on ignition á281ñ: not more than 0.5%.
Chromatographic purity—
METHODA—
Test solution— Prepare a solution of Alprazolam in chloroform containing about 2mg per mL.
Chromatographic system(see Chromatography á621ñ)— The gas chromatograph is equipped with a flame-ionization detector,and contains a 3-mm ×120-cm glass column packed with 3%phase G6on support S1AB.The column and injector port are maintained at a temperature of about 240.The detector is maintained at a temperature about 20to 50above 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 4µLof 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,...rIare the responses for each peak other than the alprazolam peak present in the Test solution;and ris the response of the alprazolam peak in the Test solution.The total amount of impurities detected is not more than 1.0%.
METHODB—
Standard solutions— Prepare a 4.0mg per mLsolution of USP Alprazolam RSin chloroform.Separately dilute 1,3,and 5mLof this solution to 100mLwith chloroform to obtain 0.1%,0.3%,and 0.5%Standard solutions,respectively.
Test solution— Prepare a solution in chloroform containing 40mg per mL.
Procedure— Separately apply 10µLeach of the Test solutionand each Standard solutionto a thin-layer chromatographic plate (see Chromatography á621ñ)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 UVlight 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%.
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 Suitabilityunder Chromatography á621ñ).
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 0.25mg per mL.
Standard preparation— Dissolve an accurately weighed quantity of USP Alprazolam RSin Internal standard solution,and dilute with Internal standard solutionto obtain a solution having a known concentration of about 0.25mg per mL.Transfer 5.0mLof this solution to a 50-mLvolumetric flask,dilute with acetonitrile to volume,and mix.
Assay preparation— Transfer about 2.5mg of Alprazolam,accurately weighed,to a 10-mLvolumetric flask,dissolve in and dilute with Internal standard solutionto volume,and mix.Transfer an accurately measured quantity,about 5mL,of this solution to a 50-mLvolumetric flask,dilute with acetonitrile to volume,and mix.
Chromatographic system(see Chromatography á621ñ)— 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 2mLper 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 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C17H13ClN4in the portion of Alprazolam taken by the formula:
100C(RU/RS),
in which Cis the concentration,in mg per mL,of USP Alprazolam RSin the Standard preparation;and RUand RSare the peak response ratios of the alprazolam peak relative to the internal standard peak obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Ravi Ravichandran,Ph.D.,Senior Scientist
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 69
Pharmacopeial Forum:Volume No.27(3)Page 2509
Phone Number:1-301-816-8330