(Ph. Eur. 11.6 update)
C9H13NO2,C4H6O6 317.3 17171-57-2
Action and use
Adrenoceptor agonist.
Preparation
Metaraminol Injection
DEFINITION
Metaraminol Tartrate is (1R,2S)-2-amino-1-(3-hydroxyphenyl)propan-1-ol hydrogen (2R,3R)-tartrate. It contains not less than 99.0% and not more than 101.0% of C9H13NO2,C4H6O6, calculated with reference to the dried substance.
CHARACTERISTICS
A white, crystalline powder.
Freely soluble in water; sparingly soluble in ethanol (96%); practically insoluble in ether.
IDENTIFICATION
A. In the test for Related substances the principal spot in the chromatogram obtained with solution (2) corresponds to that in the chromatogram obtained with solution (4).
B. To 0.5 mL of a 0.05% w/v solution add 0.5 mL of phosphomolybdotungstic reagent and 5 mL of dilute sodium carbonate solution and allow to stand for 5 minutes. An intense blue colour is produced.
C. To 4 mL of a 0.05% w/v solution add 5 mL of borate buffer pH 9.6 and 1 mL of a freshly prepared 0.5% w/v solution of sodium 1,2-naphthaquinone 4-sulfonate and allow to stand for 1 minute. Add 0.2 mL of a 2% v/v solution of benzalkonium chloride solution and 5 mL of toluene and shake. A mauve colour is immediately produced in the toluene layer (distinction from phenylephrine).
TESTS
Acidity
pH of a 5% w/v solution, 3.2 to 3.5, Appendix V L.
Phenones
Absorbance of a 0.2% w/v solution at 310 nm, not more than 0.2, calculated with reference to the dried substance, Appendix II B.
Related substances
Carry out in subdued light the method for thin-layer chromatography, Appendix III A, using the following solutions in methanol.
(1) 1.0% w/v of the substance being examined.
(2) 0.050% w/v of the substance being examined.
(3) 0.0050% w/v of the substance being examined.
(4) 0.050% w/v of metaraminol tartrate BPCRS.
CHROMATOGRAPHIC CONDITIONS
(a) Use a silica gel precoated plate (Merck silica gel 60 plates are suitable).
(b) Use the mobile phase as described below.
(c) Apply 10 μL of each solution.
(d) Develop the plate to 15 cm.
(e) After removal of the plate, dry in air and spray with a solution prepared in the following manner. Mix 25 mL of a 0.45% w/v solution of sulfanilic acid in 1M hydrochloric acid with 1.5 mL of a 5% w/v solution of sodium nitrite, allow to stand for 5 minutes and mix cautiously with 25 mL of 2M sodium carbonate.
MOBILE PHASE
10 volumes of 13.5M ammonia, 80 volumes of chloroform and 80 volumes of methanol.
LIMITS
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (3) (0.5%).
Loss on drying
When dried to constant weight at 105°, loses not more than 0.5% of its weight. Use 1 g.
Sulfated ash
Not more than 0.1%, Appendix IX A.
ASSAY
Carry out Method I for non-aqueous titration, Appendix VIII A, using 0.6 g and crystal violet solution as indicator. Each mL of 0.1M perchloric acid VS is equivalent to 31.73 mg of C9H13NO2,C4H6O6.
