Action and use
Bile acid; treatment of gallstones.
DEFINITION
Ursodeoxycholic Acid Oral Suspension is a suspension of Ursodeoxycholic Acid in a suitable vehicle.
The oral suspension complies with the requirements stated under Oral Liquids and with the following requirements.
Content of ursodeoxycholic acid, C24H40O4
95.0 to 105.0% of the stated amount.
Shake the oral suspension vigorously before carrying out the following tests.
IDENTIFICATION
A. Weigh a quantity of the oral suspension containing 50 mg of Ursodeoxycholic Acid into a test tube, add 5 mL of sulfuric acid and allow to dissolve. Add 0.5 mL formaldehyde solution, allow to stand for 5 minutes and add 25 mL water. The suspension obtained is greyish-blue.
B. In the Assay, the chromatogram obtained with solution (1) shows a peak with the same retention time as the principal peak in the chromatogram obtained with solution (2).
TESTS
Acidity
pH, 3.8 to 5.2, Appendix V L.
Related substances
Carry out the method for liquid chromatography, Appendix III D, using the following solutions in Solvent A.
Solvent A: 20 volumes of methanol and 80 volumes of mobile phase.
(1) Add a quantity of the oral suspension containing 250 mg of Ursodeoxycholic Acid to 15 mL of Solvent A and mix with the aid of ultrasound for 15 minutes. Dilute to 50 mL and filter (0.45-μm PVDF filter is suitable).
(2) Dilute 1 volume of solution (1) to 100 volumes.
(3) 0.5% w/v of ursodeoxycholic acid impurity standard BPCRS and 0.0055% w/v of chenodeoxycholic acid BPCRS (impurity A).
(4) Dilute 1 volume of solution (2) to 10 volumes.
CHROMATOGRAPHIC CONDITIONS
(a) Use a stainless steel column (10 cm × 2.1 mm) packed with octadecylsilyl silica gel for chromatography (3 μm) (Uptisphere HDO C18 is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 0.6 mL per minute.
(d) Use a column temperature of 40°.
(e) Use a refractive index detector.
(f) Inject 8 μL of each solution.
(g) For solution (1), allow the chromatography to proceed for 5 times the retention time of ursodeoxycholic acid.
MOBILE PHASE
25 volumes of acetonitrile, 34 volumes of methanol and 47 volumes of a solution prepared by dissolving 0.8 g of sodium dihydrogen orthophosphate dihydrate in 1000 mL of water and adjusting the pH to 3.0 with orthophosphoric acid.
When the chromatograms are recorded under the prescribed conditions the retention time relative to ursodeoxycholic acid (retention time, about 5 minutes) are: 7-ketolithocholic acid (impurity F), about 1.3 and chenodeoxycholic acid, about 2.8.
SYSTEM SUITABILITY
The test is not valid unless, in the chromatogram obtained with solution (3), the resolution between the peaks due to ursodeoxycholic acid and 7-ketolithocholic acid is at least 2.0.
LIMITS
In the chromatogram obtained with solution (1):
the area of any peaks corresponding to chenodeoxycholic acid is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1.0%);
the area of any other secondary peak is not greater than 0.2 times the area of the principal peak in the chromatogram obtained with solution (2) (0.2%);
the sum of the areas of any other secondary peaks is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1.0%).
Disregard any peak with an area less than the area of the principal peak in the chromatogram obtained with solution (4) (0.1%).
ASSAY
Carry out the method for liquid chromatography, Appendix III D, using the following solutions in Solvent A, as described under Related substances.
(1) Add a weighed quantity of the oral suspension containing 250 mg of Ursodeoxycholic Acid to 15 mL of Solvent A and mix with the aid of ultrasound for 15 minutes. Dilute to 50 mL and filter (0.45-μm PVDF filter is suitable).
(2) 0.5% w/v of ursodeoxycholic acid BPCRS.
(3) 0.5% w/v of ursodeoxycholic acid impurity standard BPCRS.
CHROMATOGRAPHIC CONDITIONS
The conditions described under Related substances may be used.
SYSTEM SUITABILITY
The test is not valid unless, in the chromatogram obtained with solution (3), the resolution between the peaks due to ursodeoxycholic acid and 7-ketolithocholic acid is at least 2.0.
DETERMINATION OF CONTENT
Determine the weight per mL of the oral suspension, Appendix V G, and calculate the content of C24H40O4, weight in volume, using the declared content of C24H40O4 in ursodeoxycholic acid BPCRS.
IMPURITIES
The impurities limited by the requirements of this monograph include A, D, E and F listed under Ursodeoxycholic Acid and the following:
1. 3,7,12-trioxo-(5β)-cholan-24-oic acid (dehydrocholic acid).
