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Category Antibacterial; antirickettsial.

Chloramphenicol Sodium Succinate contains not
less than 98.0 per cent and not more than 102.0 per cent
of C₁₅H₁₅Cl₂N₂O₈.Na, calculated on the anhydrous
basis.

Description White or yellowish white powder; hygroscopic.

Solubility Very soluble in water; freely soluble in ethanol; practically insoluble in ether.

Stability It is very hygroscopic. In aqueous solutions, it loses the potency relatively rapidly especially at higher temperatures.

Warning; Precaution See under Chloramphenicol, p. 63.

Packaging and storage Chloramphenicol Sodium Succinate shall be kept in tightly closed containers under sterile condition, protected from light.

Labelling The label on the container states (1) storage condition; (2) parenteral grade.

Identification
          A. The ultraviolet absorption spectrum of a 0.002 per cent w/v solution, when observed between 230 and 350 nm, exhibits a maximum only at 276 nm; the absorbance of a 1-cm layer at this wavelength is about 0.43 (Appendix 2.2).
          B. Dissolve 10 mg in 2 ml of ethanol (50 per cent), and add 4.5 ml of 1 M sulfuric acid and 50 mg of zinc powder. Allow to stand for 10 minutes, and decant the supernatant liquid or filter if necessary. Cool the resulting solution in ice and add 0.5 ml of sodium nitrite TS. After 2 minutes, add 1 g of urea followed by 1 ml of 2-naphthol TS and 2 ml of 10 M sodium hydroxide: a red colour develops. Repeat the test omitting the zinc powder: no red colour is produced.
          C. To 5 ml of a 0.1 per cent w/v solution, add a few drops of 0.1 M silver nitrate: no precipitate is produced. Then heat 50 mg with 2 ml of ethanolic potassium hydroxide TS on a water-bath for 15 minutes. Add 15 mg of decolourizing charcoal, shake, and filter. The filtrate, when treated with 0.1 M silver nitrate, yields a curdy precipitate which is insoluble in nitric acid, but soluble, after being well washed with water, in 5 M ammonia from which it is reprecipitated by the addition of nitric acid.
          D. To 100 mg, add 200 mg of resorcinol and 4 drops of sulfuric acid. Heat gently until a deep red solution is produced, and then pour the solution carefully into a large volume of water: an orange-yellow solution with an intense green fluorescence is produced.
          E. It yields the reactions characteristic of sodium salts (Appendix 5.1).

pH 6.4 to 7.0, in a 25 per cent w/v solution (Appendix 4.11).

Specific rotation +5.0^º to +8.0^º, calculated on the
anhydrous basis, determined in a 5.0 per cent w/v
solution (Appendix 4.8).

Water Not more than 5.0 per cent w/w (Karl Fischer
Method, Appendix 4.12).

Chloramphenicol and chloramphenicol disodium disuccinate Not more than 2.0 per cent of each. Carry out the test as described in the “High-Pressure Liquid Chromatography” (Appendix 3.5).
          Mobile phase Mix 5 volumes of a 2 per cent w/v solution of phosphoric acid, 40 volumes of methanol and 55 volumes of water.
          Reference solution (a) Dissolve 10.0 mg of Chloramphenicol RS in Mobile phase and dilute to 100.0 ml with Mobile phase (stock solution A). Dilute 5.0 ml of this solution to 100.0 ml with Mobile phase.
          Reference solution (b) Dissolve 10.0 mg of Chloramphenicol Disodium Disuccinate RS in Mobile phase and dilute to 100.0 ml with Mobile phase (stock solution B). Dilute 5.0 ml of this solution to 100.0 ml with Mobile phase.
          Reference solution (c) Dissolve 25 mg of the test substance in Mobile phase, add 5 ml of stock solution A and 5 ml of stock solution B and dilute to 100 ml with Mobile phase.
          Test solution Dissolve 25.0 mg of the test substance in Mobile phase and dilute to 100.0 ml with Mobile phase.

          Chromatographic system The chromatographic procedure may be carried out using (a) stainless steel column (25 cm × 4.6 mm) packed with octadecylsilyl silica gel for chromatography (5 μm), (b) Mobile phase at a flow rate of about 1 ml per minute, (c) an ultraviolet photometer set at 275 nm, and (d) a 20 μl fixed-loop injector.

          Procedure Separately inject the test solution and each of the reference solutions. The test is not valid unless, in the chromatogram obtained from reference solution (c), the two peaks corresponding to those in the chromatograms obtained from reference solutions (a) and (b) are clearly separated from the peaks corresponding to the two principal peaks in the chromatogram obtained from the test solution. If necessary, adjust the methanol content of the mobile phase.
          In the chromatogram obtained from the test solution the areas of any peaks corresponding to chloramphenicol and chloramphenicol disodium disuccinate are not greater than those of the principal peaks in the chromatograms obtained from Reference solutions (a) and (b) respectively.

Assay
          Standard preparation Dissolve an accurately weighed quantity of Chloramphenicol RS in water and dilute quantitatively with water to obtain a solution having a known concentration of about 20 μg per ml.
          Assay preparation Dissolve about 200 mg of Chloramphenicol Sodium Succinate, accurately weighed, in water, add sufficient water to produce 500.0 ml. Dilute 5.0 ml of the solution to 100.0 ml with water.
          Procedure Concomitantly measure the absorbances of Standard preparation at the maximum at about 278 nm and Assay preparation at the maximum at about 276 nm, using water as the blank (Appendix 2.2).
          Calculation Calculate the content of C₁₅H₁₅Cl₂N₂O₈.Na in the Chloramphenicol Sodium Succinate taken, using the declared content of C₁₁H₁₂Cl₂N₂O₅ in Chloramphenicol RS. Each mg of C₁₁H₁₂Cl₂N₂O₅ is equivalent to 1.3778 mg of C₁₅H₁₅Cl₂N₂O₈.Na.

Other requirements Chloramphenicol Sodium Succinate intended for parenteral administration complies with the following additional requirements.
          Bacterial endotoxins When tested as described in the “Test for Bacterial Endotoxins” (Appendix 8.5), it contains not more than 0.20 Endotoxin Unit per mg of chloramphenicol.
          Sterility Complies with the “Sterility Test” (Method I, Appendix 10.1).