Ibuprofen Tablets

General Notices

Action and use

Cyclo-oxygenase inhibitor; analgesic; anti-inflammatory.

Definition

Ibuprofen Tablets contain Ibuprofen. They are coated.

The tablets comply with the requirements stated under Tablets and with the following requirements.

Content of ibuprofen, C13H18O2

95.0 to 105.0% of the stated amount.

Identification

A. Extract a quantity of the powdered tablets containing 0.5 g of Ibuprofen with 20 mL of acetone, filter and evaporate the filtrate to dryness in a current of air without heating. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of ibuprofen (RS 186).
B. Melting point of the residue obtained in test A, after recrystallisation from petroleum spirit (boiling range, 40° to 60°), about 75°, Appendix V A.

Test

Related substances

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

(1) Add 30 mL of methanol to a quantity of the powdered tablets containing 0.2 g of Ibuprofen, shake for 30 minutes, add 30 mL of methanol and sufficient water to produce 100 mL, mix and filter through a glass microfibre filter paper (Whatman GF/C is suitable).
(2) Dilute 1 volume of solution (1) to 100 volumes with the mobile phase.
(3) Dissolve 50 mg of ibuprofen BPCRS in 2.5 mL of a 0.006% w/v solution of ibuprofen impurity B BPCRS in methanol (prepared by diluting 1 volume of ibuprofen impurity B BPCRS to 10 volumes with methanol) and add sufficient methanol to produce 25 mL.
chromatographic conditions
(a) Use a stainless steel column (15 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (Spherisorb ODS 2 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 214 nm.
(f) Inject 20 µL of each solution.
(g) Equilibrate the column with the mobile phase for about 45 minutes before starting the chromatography.
(h) Allow the chromatography to proceed for 1.5 times the retention time of the principal peak. When the chromatograms are recorded under the conditions described above, the retention time of ibuprofen is about 20 minutes.
mobile phase

0.5 volume of orthophosphoric acid, 340 volumes of acetonitrile and 600 volumes of water diluted to 1000 volumes with water after equilibration.

system suitability

In the chromatogram obtained with solution (3) measure the height (a) of the peak due to 2-(4-butylphenyl)-propionic acid and the height (b) of the lowest point of the curve separating this peak from that due to ibuprofen. The test is not valid unless a is greater than 1.5b. If necessary, adjust the concentration of acetonitrile in the mobile phase to obtain the required resolution.

limits

In the chromatogram obtained with solution (1):

the area of any peak corresponding to ibuprofen impurity B is not greater than the area of the corresponding peak in the chromatogram obtained with solution (3) (0.3%);

the area of any other secondary peak is not greater than 0.3 times the area of the principal peak in the chromatogram obtained with solution (2) (0.3%);

the sum of the area of any secondary peaks, other than the peak due to impurity B, is not greater than 0.7 times the area of the principal peak in the chromatogram obtained with solution (2) (0.7%).

Disregard any peak the area of which is less than 0.1 times the area of the principal peak in the chromatogram obtained with solution (2) (0.1%).

Assay

Weigh and powder 20 tablets. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.

(1) Shake a quantity of the powdered tablets containing 0.2 g of Ibuprofen with 30 mL of the mobile phase for 30 minutes, add sufficient of the mobile phase to produce 100 mL and mix thoroughly. Centrifuge 25 mL of the solution at 2500 g for 5 minutes and use the supernatant liquid.
(2) 0.2% w/v of ibuprofen BPCRS in the mobile phase.
chromatographic conditions
(a) Use a stainless steel column (25 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (10 µm) (Nucleosil C18 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1.5 mL per minute.
(d) Use an ambient column temperature.
(e) Use a detection wavelength of 264 nm.
(f) Inject 20 µL of each solution.
mobile phase

3 volumes of orthophosphoric acid, 247 volumes of water and 750 volumes of methanol.

determination of content

Calculate the content of C13H18O2 using the declared content of C13H18O2 in ibuprofen BPCRS.

Impurities

The impurities limited by the requirements of this monograph include:

1. (2RS)-2-(4-butylphenyl)propanoic acid (Ibuprofen Impurity B).