Epitetracycline Hydrochloride
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2-Naphthacenecarboxamide,4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,6,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-,monohydrochloride,[4R-(4a,4ab,5ab,6a,12ab)]-.
(4R,4aS,5aS,6S,12aS)4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,6,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide monohydrochloride [23313-80-6].
»Epitetracycline Hydrochloride contains not less than 70.0percent of C22H24N2O8·HCl.
Packaging and storage—
Preserve in tight,light-resistant containers.
pHá791ñ:
between 2.3and 4.0,in a solution containing 10mg per mL.
Loss on drying á731ñ—
Dry about 100mg in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60
for 3hours:it loses not more than 6.0%of its weight.
for 3hours:it loses not more than 6.0%of its weight.
4-Epianhydrotetracycline á226ñ—
Dissolve about 250mg,accurately weighed,in 10mLof 0.1Nhydrochloric acid,and adjust with 6Nammonium hydroxide to a pHof 7.8.Transfer this solution with the aid of EDTAbufferto a 50-mLvolumetric flask,dilute with EDTAbufferto volume,and mix.Use this solution,without delay,as the Test solution:not more than 2.0%is found.
Assay—
Edetate disodium solution
,Stationary phase,Alkaline methanol solution,Column support,Chromatographic column,and Standard preparation—Prepare as directed in the section Epitetracycline hydrochloride content and Assay for tetracycline hydrochlorideunder Tetracycline Hydrochloride for Topical Solution.
Assay preparation—
Transfer about 22mg of Epitetracycline Hydrochloride,accurately weighed,to a 25-mLvolumetric flask,add 1mLof methanol,and swirl to dissolve.Dilute with Stationary phaseto volume,and mix.Transfer 2.0mLof this solution to a 10-mLvolumetric flask,dilute with Stationary phaseto volume,and mix.Pipet 2.0mLof this solution into the Chromatographic column,and allow it to penetrate the Column support.Add 20mLof benzene to the solvent reservoir,and collect the eluate at the rate of about 1mLper minute.When the benzene level reaches the top of the Column support,add 60mLof chloroform to the solvent reservoir,and continue collecting eluate.When the chloroform level reaches the top of the Column support,discard the collected eluate,add 50mLof a mixture of butyl alcohol and methanol (1:1),and collect 8mLof eluate in a 10-mLgraduated cylinder.Replace the 10-mLgraduated cylinder with a low-actinic 50-mLvolumetric flask,and continue collecting eluate until the column runs dry.The eluate in the 50-mLvolumetric flask is the Assay preparation.
Procedure—
Add 2.0mLof Alkaline methanol solutionto the Standard preparationand to the Assay preparation,dilute each with chloroform to volume,and mix.Concomitantly,within 10minutes of preparation,determine the absorbances of these solutions at the wavelength of maximum absorbance at about 366nm,with a suitable spectrophotometer,using chloroform as the blank.Calculate the quantity,in mg,of C22H24N2O8·HCl in the Epitetracycline Hydrochloride taken by the formula:
0.001(WP)(AU/AS),
in which Wis the weight,in mg,of USP Tetracycline Hydrochloride RStaken,Pis the potency,in µg per mg,of the USP Tetracycline Hydrochloride RS,and AUand ASare the absorbances of the solutions from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information—
Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 744
Phone Number:1-301-816-8335