日文名：ウラピジル
结构式：
C20H29N5O3: 387.48
6-{3-[4-(2-Methoxyphenyl) piperazin-1-yl] propylamino}-1,3-dimethyluracil
CAS No. 34661-75-1
Urapidil, when dried, contains not less than 98.0% and not more than 101.0% of urapidil (C20H29N5O3)
1. Description
Urapidil occurs as white to pale yellowishwhite, crystals or crystalline powder. It has a bitter taste. It is freely soluble in acetic acid (100), sparingly soluble inethanol (95) and in acetone, and very slightly soluble inwater.
2. Identification
1) Determine the absorption spectrum of asolution of Urapidil in ethanol (95) (1 in 100,000) as directedunder Ultraviolet-visible Spectrophotometry <2.24>, andcompare the spectrum with the Reference Spectrum: bothspectra exhibit similar intensities of absorption at the samewavelengths.
2) Determine the infrared absorption spectrum of Urapidil as directed in the potassium bromide disk methodunder Infrared Spectrophotometry <2.25>, and compare thespectrum with the Reference Spectrum: both spectra exhibitsimilar intensities of absorption at the same wave numbers.
3. Melting point <2.60>
156 – 161℃
4. Purity
1) Chloride <1.03>
Dissolve 3.0 g of Urapidil in40 mL of acetone and 6 mL of dilute nitric acid, add waterto make 50 mL, and perform the test using this solution asthe test solution. Prepare the control solution as follows. To 0.25 mL of 0.01 mol/L hydrochloric acid VS add 40 mL ofacetone, 6 mL of dilute nitric acid and water to make 50 mL (not more than 0.003%).
2) Heavy metals <1.07>
Proceed with 1.0 g of Urapidilaccording to Method 4, and perform the test. Prepare the control solution with 2.0 mL of Standard Lead Solution (not more than 20 ppm).
3) Related substances
Dissolve 40 mg of Urapidil in 5 mL of ethanol (95), and use this solution as the sample solution. Pipet 1 mL of the sample solution, add ethanol (95) to make exactly 200 mL, and use this solution as the standard solution. Perform the test with these solutions as directed under Thin-layer Chromatography <2.03>. Spot 5 mL each of the sample solution and standard solution on a plate of silica gel with fluorescent indicator for thin-layer chromatography, develop with a mixture of ethyl acetate, ethanol (95) and ammonia water (28) (22:13:1) to a distance of about 15 cm, and air-dry the plate. Examine under ultraviolet light (main wavelength: 254 nm): the spot other than the principal spot from the sample solution appears not more than one and it is not more intense than the spot from the standard solution.
5. Loss on drying <2.41>
Not more than 0.5z (1 g, 105℃, 3 hours).
6. Residue on ignition <2.44>
Not more than 0.2% (1 g).
7. Assay Weigh accurately about 70 mg of Urapidil, previously dried, dissolve in 80 mL of acetic acid (100), and titrate <2.50> with 0.1 mol/L perchloric acid VS (potentiometric titration). Perform a blank determination in the same manner, and make any necessary correction.
Each mL of 0.1 mol/L perchloric acid VS
＝12.92 mg of C20H29N5O3
8. Containers and storage
Containers—Tight containers.
