Action and use
Fluoroquinolone antibacterial.
DEFINITION
Ofloxacin Eye Drops are a sterile solution of Ofloxacin in a suitable vehicle.
The eye drops comply with the requirements stated under Eye Preparations and with the following requirements.
Content of ofloxacin, C18H20FN3O4
93.0 to 107.0% of the stated amount.
IDENTIFICATION
In the Assay, record the UV spectrum of the principal peak in the chromatograms obtained with solutions (1) and (2) with a diode array detector in the range of 210 to 400 nm.
The UV spectrum of the principal peak in the chromatogram obtained with solution (1) is concordant with that of the peak in the chromatogram obtained with solution (2);
the retention time of the principal peak in the chromatogram obtained with solution (1) is similar to that of the peak in the chromatogram obtained with solution (2).
TESTS
Related substances
Carry out the method for liquid chromatography, Appendix III D, using the following solutions prepared in solution A.
Solution A: 10 volumes of acetonitrile and 90 volumes of 0.01M hydrochloric acid.
Solution B: 0.308% w/v of ammonium acetate and 0.538% w/v of sodium perchlorate in water, adjusted to pH 2.2 using orthophosphoric acid.
(1) Dilute a suitable volume of the eye drops to produce a solution containing 0.04% w/v of Ofloxacin.
(2) Dilute 1 volume of solution (1) to 200 volumes.
(3) 0.00008% w/v each of ofloxacin impurity D EPCRS and ofloxacin impurity E EPCRS and 0.0002% w/v of ofloxacin BPCRS.
(4) Dilute 1 volume of solution (2) to 5 volumes.
CHROMATOGRAPHIC CONDITIONS
(a) Use a stainless steel column (15 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (3 μm) (YMC Pack Pro C18 is suitable).
(b) Use gradient elution and the mobile phase described below.
(c) Use a flow rate of 1.0 mL per minute.
(d) Use a column temperature of 38°.
(e) Use a detection wavelength of 294 nm.
(f) Inject 10 μL of each solution.
MOBILE PHASE
Mobile phase A: 16 volumes of acetonitrile and 84 volumes of solution B.
Mobile phase B: 20 volumes of methanol, 30 volumes of acetonitrile and 50 volumes of solution B.
| Time (Minutes) | Mobile phase A (% v/v) | Mobile phase B (% v/v) | Comment |
| 0-5 | 100 | 0 | isocratic |
| 5-10 | 100→82 | 0→18 | linear gradient |
| 10-15 | 82→40 | 18→60 | linear gradient |
| 15-30 | 40 | 60 | isocractic |
| 30-32 | 40→100 | 60→0 | linear gradient |
| 32-40 | 100 | 0 | re-equilibration |
SYSTEM SUITABILITY
The test is not valid unless:
in the chromatogram obtained with solution (3), the resolution between the peaks due to impurity E and ofloxacin is at least 2.0 and;
in the chromatogram obtained with solution (4), the signal-to-noise ratio of the peak due to ofloxacin is at least 90.
CALCULATION OF IMPURITIES
For each impurity, use the concentration of ofloxacin in solution (2).
For the reporting threshold, use the concentration of ofloxacin in solution (4).
For peak identification, use solution (3).
Ofloxacin retention time: about 10 minutes.
Relative retention: impurity D, about 0.7; impurity E, about 0.9.
Correction factors: impurity D, multiply by 4.5.
LIMITS
— impurity D: not more than 0.2%;
— up to one impurity: not more than 0.8%
— any other impurities: not more than 0.2%;
— total impurities: not more than 1.0%;
— reporting threshold: 0.1%.
ASSAY
Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
(1) Dilute a suitable volume of the eye drops with 10% v/v of acetonitrile to produce a solution containing 0.001% w/v of Ofloxacin.
(2) Prepare a 0.1% w/v solution of ofloxacin BPCRS in methanol and dilute 1 volume of this solution to 100 volumes with 10% v/v of acetonitrile.
CHROMATOGRAPHIC CONDITIONS
(a) Use a stainless steel column (10 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (3.5 μm) (Symmetry C18 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 2.0 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 294 nm.
(f) Inject 20 μL of each solution.
MOBILE PHASE
10 volumes of acetonitrile and 90 volumes of a solution containing 2.72% w/v of potassium dihydrogen orthophosphate, previously adjusted to pH 3.3 with orthophosphoric acid.
SYSTEM SUITABILITY
The test is not valid unless, in the chromatogram obtained with solution (2), the symmetry factor of the principal peak is not greater than 2.0.
DETERMINATION OF CONTENT
Calculate the content of ofloxacin, C18H20FN3O4, in the eye drops from the chromatograms obtained and using the declared content of C18H20FN3O4 in ofloxacin BPCRS.
IMPURITIES
The impurities limited by the requirements of this monograph include impurities B, C, D, E and F listed under Ofloxacin.
