Mesalazine Suppositories

Aminosalicylate; treatment of ulcerative colitis.

Mesalazine Suppositories contain Mesalazine in a suitable suppository basis.

The suppositories comply with the requirements stated under Rectal Preparations and with the following requirements.

95.0 to 105.0% of the stated amount.

Boil a quantity of the suppositories containing 1.0 g of Mesalazine with 50 mL of water until completely melted and filter the hot supernatant fluid. Cool the solution to room temperature, allow to stand, filter and dry at 110°. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of mesalazine (RS 454).

Carry out the method for liquid chromatography, Appendix III D, using the following solutions prepared immediately before use.

(1) Mix with the aid of ultrasound, a quantity of the suppositories containing 1 g of Mesalazine in 750 mL of 0.01m hydrochloric acid until the suppositories disintegrate, add sufficient 0.01m hydrochloric acid to produce 1 L, mix using a vortex mixer and filter through a 0.45 µm membrane filter.

(2) Dilute 1 volume of solution (1) to 100 volumes with 0.01m hydrochloric acid and further dilute 1 volume of the resulting solution to 10 volumes with 0.01m hydrochloric acid.

(3) Dilute 1 volume of a 0.01% w/v solution of 3-aminosalicylic acid (impurity F) in 0.01m hydrochloric acid to 100 volumes with solution (1).

(4) 0.0001% w/v each of 4-aminosalicylic acid (impurity E), 2,5-dihydroxybenzoic acid (impurity G), 2-chlorobenzoic acid (impurity L), 2-chloro-5-nitrobenzoic acid (impurity M), 5-nitrosalicylic acid (impurity N), sulfanilic acid (impurity O), 3-nitrosalicylic acid (impurity R) and 0.0003% w/v of salicylic acid (impurity H) in 0.01m hydrochloric acid.

(5) 0.01% w/v of mesalazine for peak identification EPCRS in 0.01m hydrochloric acid.

(a) Use a stainless steel column (25 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (X-Terra MS C18 is suitable).

(b) Use gradient elution and the mobile phases described below.

(c) Use a flow rate of 1 mL per minute.

(d) Use a column temperature of 40°.

(e) Use a detection wavelength of 240 nm.

(f) Inject 20 µL of each solution.

Mobile phase A  A 0.69% w/v solution of sodium dihydrogen phosphate monohydrate, adjusted to pH 6.2 with dilute sodium hydroxide.

Mobile phase B  40 volumes of acetonitrile and 60 volumes of mobile phase A.

Use the chromatogram obtained with solution (3) to identify the peak due to impurity F; use the chromatogram obtained with solution (4) to identify the peaks due to impurities E, G, H, L, M, N, O and R; use the chromatogram supplied with mesalazine for peak identification EPCRS and the chromatogram obtained with solution (5) to identify the peaks due to impurities J and P.

When the chromatograms are recorded under the prescribed conditions, the relative retentions with reference to mesalazine (retention time = about 6 minutes) are: impurity O = about 0.55; impurity J = about 0.6; impurity E = about 0.8; impurity F = about 1.36; impurity G = about 1.4; impurity P = about 1.5; impurity L = about 2.0; impurity M = about 3.3; impurity H = about 3.5; impurity R = about 5.1; impurity N = about 5.5.

In the chromatogram obtained with solution (3):

the peak-to-valley ratio is at least 3.0, where H_p is the height above the baseline of the peak due to impurity F and H_v is the height above the baseline of the lowest point of the curve separating this peak from the peak due to mesalazine.

Identify any peaks in the chromatogram obtained with solution (1) corresponding to impurities E, G, H, J, L, M, O, P and R using solutions (4) and (5) and multiply the area of these peaks by the corresponding correction factors: impurity E, 1.3; impurity G, 1.4; impurity H, 1.4; impurity J, 2.0; impurity L, 4.5; impurity M, 1.7; impurity O, 0.6; impurity P, 0.6; impurity R, 1.3.

In the chromatogram obtained with solution (1):

the area of any peak corresponding to impurity H is not greater than 3 times the area of the principal peak in the chromatogram obtained with solution (2) (0.3%);

the area of any peak corresponding to impurity E, F, G, J, L, M, P or R is not greater than 1.5 times the area of the principal peak in the chromatogram obtained with solution (2) (0.15%);

the area of any other secondary peak is not greater than half the area of the principal peak in the chromatogram obtained with solution (2) (0.1%);

the sum of the areas of any secondary peaks is not greater than 5 times the area of the principal peak in the chromatogram obtained with solution (2) (0.5 %).

Disregard any peak with an area less than half the area of the principal peak in the chromatogram obtained with solution (2) (0.05%).

Carry out the method for liquid chromatography, Appendix III D, using the following solutions and freshly prepared mobile phases.

(1) Cut a suitable number of the suppositories containing 50 mg of Mesalazine into small pieces, add 25 mL of mobile phase A, mix for 10 minutes with the aid of ultrasound and occasional shaking, add sufficient mobile phase A to produce 50 mL, shake for 30 seconds and filter through a 0.45-µm membrane filter.

(2) Mix 1 volume of a 0.002% w/v solution of 4-aminophenol (impurity A) in mobile phase A with 1 volume of 0.002% w/v of 2-aminophenol (impurity C) in mobile phase A, add sufficient mobile phase A to produce 100 volumes and mix.

(3) To 1 volume of solution (1) add sufficient of mobile phase A to produce 200 volumes, mix 1 volume of this solution with 1 volume of 0.0005% w/v of 2-aminophenol in mobile phase A.

(a) Use a stainless steel column (25 cm × 4.6 mm) packed with spherical end-capped octadecylsilyl silica gel for chromatography (3 µm) (Nucleosil C18 is suitable).

(b) Use gradient elution and the mobile phase described below.

(c) Use a flow rate of 1 mL per minute.

(d) Use an ambient column temperature.

(e) Use a detection wavelength of 220 nm.

(f) Inject 20 µL of each solution.

When the chromatograms are recorded under the prescribed conditions, the relative retentions with reference to mesalazine (retention time = about 9 minutes) are: impurity A = about 0.5; impurity C = about 0.9.

Mobile phase A  A solution containing 0.22% w/v perchloric acid and 0.1% w/v phosphoric acid.

Mobile phase B  A solution containing 0.17% w/v perchloric acid and 0.1% w/v phosphoric acid in acetonitrile R1.

The test is not valid unless, in the chromatogram obtained with solution (3), the resolution factor between the two principal peaks is at least 3.0.

In the chromatogram obtained with solution (1):

the area of any peak corresponding to impurity A is not greater than the area of any corresponding peak in the chromatogram obtained with solution (2) (200 ppm);

the area of any peak corresponding to impurity C is not greater than 4 times the area of any corresponding peak in the chromatogram obtained with solution (2) (200 ppm).

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

(1) Cut a suitable number of the suppositories containing 50 mg of Mesalazine into small pieces, add 5 drops of 1m sodium hydroxide and 15 mL of the mobile phase, mix for 20 minutes with the aid of ultrasound, add sufficient of the mobile phase to produce 25 mL and filter through a 0.45 µm membrane filter.

(2) 0.00000278% w/v of aniline hydrochloride in the mobile phase.

(a) Use a stainless steel column (25 cm × 4 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (Lichrospher RP18e is suitable).

(b) Use isocratic elution and the mobile phase described below.

(c) Use a flow rate of 1 mL per minute.

(d) Use a column temperature of 40°.

(e) Use a detection wavelength of 205 nm.

(f) Inject 50 µL of each solution.

The retention time of aniline is about 15 minutes.

15 volumes of methanol and 85 volumes of a solution containing 0.141% w/v of potassium dihydrogen orthophosphate and 0.047% w/v of disodium hydrogen orthophosphate dihydrate previously adjusted to pH 8.0 with 4.2% w/v of sodium hydroxide.

In the chromatogram obtained with solution (1):

the area of any peak corresponding to aniline (impurity K) is not greater than the area of any corresponding peak in the chromatogram obtained with solution (2) (10 ppm).

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

(1) Cut a suitable number of the suppositories containing 100 mg of Mesalazine into small pieces and add 75 mL of 0.1m hydrochloric acid, mix for 50 minutes with the aid of ultrasound with additional vortex mixing at 10 minute intervals; add sufficient 0.1m hydrochloric acid to produce 100 mL, mix and filter through a 0.45 µm membrane filter. To 1 volume of the filtrate add sufficient 0.1m hydrochloric acid to produce 50 volumes.

(2) 0.002% w/v of mesalazine BPCRS prepared by dissolving in 0.1m hydrochloric acid with the aid of ultrasound.

(3) Prepare a 0.01% w/v of 3-aminosalicylic acid in 0.1m hydrochloric acid and dilute 1 volume of this solution to 100 volumes with a 0.1% w/v solution of mesalazine BPCRS in 0.1m hydrochloric acid.

(a) Use a stainless steel column (25 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (XTerra MS C18 is suitable).

(b) Use isocratic elution and the mobile phase described below.

(c) Use a flow rate of 1 mL per minute.

(d) Use a column temperature of 40°.

(e) Use a detection wavelength of 240 nm.

(f) Inject 20 µL of each solution.

A 0.69% w/v solution of sodium dihydrogen phosphate monohydrate, adjusted to pH to 6.2 with dilute sodium hydroxide solution.

In the chromatogram obtained with solution (3):

the peak-to-valley ratio is at least 3.0, where H_p is the height above the baseline of the peak due to 3-aminosalicylic acid and H_v is the height above the baseline of the lowest point of the curve separating this peak from the peak due to mesalazine.

Calculate the content of C₇H₇NO₃ in the suppositories using the declared content of C₇H₇NO₃ in mesalazine BPCRS.

The impurities limited by the requirements of this monograph include those listed under Mesalazine.