Chloramphenicol Capsules

General Notices

Action and use

Antibacterial.

Definition

Chloramphenicol Capsules contain Chloramphenicol.

The capsules comply with the requirements stated under Capsules and with the following requirements.

Content of chloramphenicol, C11H12Cl2N2O5

95.0 to 105.0% of the stated amount.

Identification

Suspend a quantity of the contents of the capsules containing 0.1 g of Chloramphenicol in 60 mL of water and extract with two 20-mL quantities of petroleum spirit (boiling range, 120° to 160°). Wash the combined extracts with two 15-mL quantities of water, add the washings to the aqueous layer, extract with four 50-mL quantities of ether and evaporate the combined ether extracts. The residue complies with the following tests.

A. Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions in ethanol (96%).
(1) 1% w/v of the residue.
(2) 1% w/v of chloramphenicol BPCRS.
chromatographic conditions
(a) Use as the coating silica gel GF254.
(b) Use the mobile phase as described below.
(c) Apply 1 µL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, allow it to dry in air and examine under ultraviolet light (254 nm).
mobile phase

1 volume of water, 10 volumes of methanol and 90 volumes of chloroform.

confirmation

The principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).

B. Dissolve 10 mg of the residue in 2 mL of ethanol (50%), add 4.5 mL of 1m sulfuric acid and 50 mg of zinc powder and allow to stand for 10 minutes. Decant the supernatant liquid or filter if necessary. Cool the resulting solution in ice and add 0.5 mL of sodium nitrite solution and, after 2 minutes, 1 g of urea followed by 1 mL of 2-naphthol solution and 2 mL of 10m sodium hydroxide; a red colour is produced. Repeat the test omitting the zinc powder; no red colour is produced.

Tests

Dissolution

Comply with the requirements for Monographs of the British Pharmacopoeia in the dissolution test for tablets and capsules, Appendix XII B1.

test conditions
(a) Use Apparatus 1, rotating the basket at 100 revolutions per minute.
(b) Use 900 mL of 0.1m hydrochloric acid, at a temperature of 37°, as the medium.
procedure

After 45 minutes withdraw a 10 mL sample of the medium and measure the absorbance of the filtered sample, suitably diluted with 0.1m hydrochloric acid if necessary, at the maximum at 278 nm, Appendix II B, using 0.1m hydrochloric acid in the reference cell.

determination of content

Calculate the total content of chloramphenicol, C11H12Cl2N2O5, in the medium taking 297 as the value of A(1%, 1 cm) at the maximum at 278 nm.

2-Amino-1-(4-nitrophenyl)propane-1,3-diol

Carry out the method for liquid chromatography, Appendix III D, using the following solutions.

(1) Shake a quantity of the contents of the capsules containing 40 mg of Chloramphenicol with 100 mL of the mobile phase for 10 minutes, add sufficient mobile phase to produce 200 mL, mix and filter.
(2) 0.0002% w/v of 2-amino-1-(4-nitrophenyl)propane-1,3-diol BPCRS in the mobile phase.
(3) 0.005% w/v of each of chloramphenicol BPCRS and 2-amino-1-(4-nitrophenyl)propane-1,3-diol BPCRS in the mobile phase.
chromatographic conditions

The chromatographic conditions described under Assay may be used.

system suitability

The test is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between the peaks corresponding to chloramphenicol and 2-amino-1-(4-nitrophenyl)propane-1,3-diol is at least 8.0.

limits

In the chromatogram obtained with solution (1):

the area of any peak corresponding to 2-amino-1-(4-nitrophenyl)-propane-1,3-diol is not greater than the area of the peak in the chromatogram obtained with solution (2) (1%).

Assay

Carry out the method for liquid chromatography, Appendix III D, using the following solutions.

(1) Dissolve a quantity of the mixed contents of 20 capsules containing 0.2 g of Chloramphenicol in 800 mL of water, warming if necessary to effect solution, and add sufficient water to produce 1000 mL. Dilute 25 mL of this solution to 50 mL with the mobile phase.
(2) Dilute 1 volume of a 0.1% w/v solution of chloramphenicol BPCRS in water to 10 volumes with the mobile phase.
(3) 0.005% w/v of each of chloramphenicol BPCRS and 2-amino-1-(4-nitrophenyl)propane-1,3-diol BPCRS in the mobile phase.
chromatographic conditions
(a) Use a stainless steel column (10 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (Nucleosil C18 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 2 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 278 nm.
(f) Inject 10 µL of each solution.
mobile phase

1 volume of glacial acetic acid, 15 volumes of acetonitrile and 85 volumes of a 0.21% w/v solution of sodium pentanesulfonate.

system suitability

The Assay is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between the peaks corresponding to chloramphenicol and 2-amino-1-(4-nitrophenyl)propane-1,3-diol is at least 8.0.

determination of content

Calculate the content of C11H12Cl2N2O5 in the capsules using the declared content of C11H12Cl2N2O5 in chloramphenicol BPCRS.