Zolazepam Hydrochloride, chemical structure, molecular formula, Reference Standards

Zolazepam Hydrochloride

C15H15FN4O·HCl 322.77

Pyrazolo[3,4-e][1,4]diazepin-7(1H)-one,4-(2-fluorophenyl)-6,8-dihydro-1,3,8-trimethyl-,monohydrochloride.
4-(o-Fluorophenyl)-6,8-dihydro-1,3,8-trimethylpyrazolo[3,4-e][1,4]diazepin-7(1H)-one monohydrochloride [33754-49-3].

»Zolazepam Hydrochloride contains not less than 97.0percent and not more than 103.0percent of C15H15FN4O·HCl.

Packaging and storage— Preserve in tight containers.

Labeling— Label it to indicate that it is for veterinary use only.Where it is intended for use in preparing injectable dosage forms,the label states that it is sterile or must be subjected to further processing during the preparation of injectable dosage forms.

USP Reference standards á11ñ— USP Endotoxin RS.USP Zolazepam Hydrochloride RS.

Clarity of solution— Dissolve 2.0g of it in 10mLof water:the solution is clear.

Identification—

A: Infrared Absorption á197Kñ.

B: Ultraviolet Absorption á197Uñ—

Solution: 0.015mg per mL.

Medium: 0.1Nhydrochloric acid.

Absorptivities at 223nm do not differ by more than 3.0%.

C: It responds to the tests for Chloride á191ñ.

Bacterial endotoxins á85ñ —Where the label states that Zolazepam Hydrochloride is sterile or must be subjected to further processing during the preparation of injectable dosage forms,it contains not more than 0.07USP Endotoxin Unit per mg of zolazepam.

Sterility á71ñ —Where the label states that Zolazepam Hydrochloride is sterile,it meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product to be Examined.

pHá791ñ: between 1.5and 3.5,in a solution (1in 10).

Loss on drying á731ñ— Dry it at 105

for 4hours:it loses not more than 1.0%of its weight.

Residue on ignition á281ñ: not more than 0.5%.

Heavy metals,Method IIá231ñ: 0.002%.

Chromatographic purity—

Modified Dragendorff's reagent— Dissolve 1.7g of bismuth subnitrate in 80mLof water and 20mLof glacial acetic acid,warming,if necessary.Cool,add 100mLof potassium iodide solution (1in 2),and mix.Refrigerate this stock solution for prolonged storage.For use,dilute 10mLof this stock solution with water to 100mL,add 10mLof glacial acetic acid,and mix.Then add 120mg of iodine crystals,and shake until the iodine has completely dissolved.Store refrigerated,and discard after 2weeks.

Procedure— Prepare a test solution of Zolazepam Hydrochloride in methanol containing 100mg per mL.Prepare a Standard solution in methanol containing 2.0mg of USP Zolazepam Hydrochloride RSper mL.Prepare a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Separately apply 5µLof the test solution and the Standard solution to the plate,and allow the spots to dry.Place the plate in a saturated chamber containing a solvent system consisting of a mixture of toluene,acetone,and ammonium hydroxide (75:18:7),and lined with filter paper.Develop the chromatogram until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber,mark the solvent front,allow the plate to air-dry.Spray the plate with Modified Dragendorff's reagent,and examine the plate:no individual secondary spot observed in the chromatogram obtained from the test solution is greater in size or intensity than the principal spot observed in the chromatogram obtained from the Standard solution,corresponding to 2%,and the total of any such spots observed does not exceed 3%.

Chloride content— Transfer about 400mg of it,accurately weighed,to a conical flask,add 5mLof water,5mLof glacial acetic acid,and 50mLof methanol,and swirl to dissolve.Add 1drop of eosin Y TS,and titrate with 0.1Nsilver nitrate VSto the endpoint when the granular precipitate first turns to a permanent pink color.Each mLof 0.1Nsilver nitrate is equivalent to 3.545mg of chloride:between 10.5%and 11.5%is found.

Assay— Transfer about 480mg of Zolazepam Hydrochloride,accurately weighed,to a conical flask,add 70mLof glacial acetic acid,10mLof mercuric acetate TS,and swirl to dissolve.Titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction (see Titrimetry á541ñ).Each mLof 0.1Nperchloric acid is equivalent to 32.28mg of C15H15FN4O·HCl.

Auxiliary Information— Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist

Expert Committee:(VET)Veterinary Drugs

USP28–NF23Page 2058

Phone Number:1-301-816-8178