Meclocycline Sulfosalicylate
(me'' kloe sye' kleen sul'' foe sa lis' i late).
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C22H21ClN2O8·C7H6O6S 695.05

2-Naphthacenecarboxamide, 7-chloro-4-(dimethylamino)- 1,4,4a,5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-6-methylene-1,11-dioxo-, [4S-(4,4a,5,5a,12a)]-, mono(2-hydroxy-5-sulfobenzoate) (salt).
(4S,4aR,5S,5aR,12aS)-7-Chloro-4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-6-methylene-1,11-dioxo-2-naphthacene carboxamide mono(5-sulfosalicylate) (salt) [73816-42-9].
» Meclocycline Sulfosalicylate has a potency equivalent to not less than 620 µg of meclocycline (C22H21ClN2O8) per mg.
Packaging and storage— Preserve in tight containers, protected from light.
USP Reference standards 11
USP Meclocycline Sulfosalicylate RS Click to View Structure
Identification, Infrared Absorption 197K.
Crystallinity 695: meets the requirements.
pH 791: between 2.5 and 3.5, in a solution containing 10 mg per mL.
Water, Method I 921: not more than 4.0%.
Assay—
0.001 M Ammonium edetate— Transfer 293 mg of edetic acid, accurately weighed, to a 1000-mL volumetric flask, add 1 mL of methanol and 7 mL of ammonium hydroxide, and shake to dissolve the edetic acid. Add 900 mL of water, adjust with glacial acetic acid to a pH of 6.6, dilute with water to volume, and mix.
Mobile phase— Prepare a mixture of 0.001 M Ammonium edetate and tetrahydrofuran (85 : 15). Filter and degas the solution before use.
Standard stock preparation— Dissolve an accurately weighed quantity of USP Meclocycline Sulfosalicylate RS in methanol to obtain a solution having a known concentration of about 0.5 mg of meclocycline per mL.
Standard preparation— Immediately prior to injection, dilute the Standard stock preparation quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 60 µg of meclocycline per mL.
Assay stock preparation— Transfer 36 mg of Meclocycline Sulfosalicylate, accurately weighed, to a 50-mL volumetric flask, dilute with methanol to volume, and mix.
Assay preparation— Immediately prior to injection, transfer 3.0 mL of the Assay stock preparation to a 25-mL volumetric flask, dilute with Mobile phase to volume, and mix to obtain a solution having a nominal concentration of about 60 µg of meclocycline per mL.
Chromatographic system— The liquid chromatograph is equipped with a 340-nm detector and a 4-mm × 25-cm column that contains packing L1. The flow rate is about 0.8 mL per minute. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation of the meclocyline peak for replicate injections is not more than 3.0%.
Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, and measure the responses for the meclocycline peak. Calculate the quantity in µg of C22H21ClN2O8 in each mg of Meclocycline Sulfosalicylate taken by the formula:
(CS / CU)(rU / rS)
in which CS is the concentration, in µg per mL, of meclocycline in the Standard preparation; CU is the concentration, in mg per mL, of Meclocycline Sulfosalicylate in the Assay preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35–NF30 Page 3778
Pharmacopeial Forum: Volume No. 34(3) Page 627