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Category Antibacterial (otic).

          Chloramphenicol Ear Drops are a sterile solution of Chloramphenicol in a suitable solvent. They contain not less than 90.0 per cent and not more than 130.0 per cent of the labelled amount of C₁₁H₁₂Cl₂N₂O₅.

Strength available 0.5 per cent w/v.

Dose Topical, to the ear canal, 2 or 3 drops every 6 to 8 hours.

Contra-indication It is contra-indicated in patients with a history of toxic reaction to chloramphenicol.

Warning It should not be used in the presence of a perforated tympanic membrane.

Precaution
          1. Long-term use of chloramphenicol otic preparation may cause bone marrow hypoplasia.
          2. If superinfection occurs, the drug should be discontinued and appropriate therapy instituted.

Packaging and storage Chloramphenicol Ear Drops shall be kept in tightly closed containers, protected from light and not be frozen.

Identification
          A. Dilute a volume of the ear drops containing 50 mg of chloramphenicol to 10 ml with ethanol (50 per cent): 2 ml of the resulting solution complies with the test for Identification A described under Chloramphenicol Capsules, p. 64.
          B. The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

pH 4.0 to 8.0, when diluted with an equal volume of water (Appendix 4.15).

Water Not more than 2.0 per cent w/w (Karl Fischer Method, Appendix 4.12).

Assay Carry out the determination as described in the “High-pressure Liquid Chromatography” (Appendix 3.5).
          Mobile phase, Chromatographic system and Procedure Proceed as directed in the Assay under Chloramphenicol, p. 64.
          Standard preparation Dissolve an accurately weighed quantity of Chloramphenicol RS in Mobile phase, and dilute quantitatively, and stepwise if necessary, with Mobile phase to obtain a solution having a known concentration of about 100 μg per ml.
          Assay preparation Transfer an accurately measured volume of Chloramphenicol Ear Drops, containing about 50 mg of chloramphenicol, to a 100-ml volumetric flask, dilute with Mobile phase to volume, and mix. Transfer 5.0 ml of the resulting solution to a 25-ml volumetric flask, dilute with Mobile phase to volume, and mix.
          Calculation Calculate the content of C₁₁H₁₂Cl₂N₂O₅ in the portion of the Ear Drops taken, using the declared content of C₁₁H₁₂Cl₂N₂O₅ in Chloramphenicol RS.

Other requirements Comply with the requirements described under “Ear Preparations” (Appendix 1.16).