A white or almost white powder, crystalline powder or colourless crystals, very slightly soluble in water, freely soluble in alcohol and in methanol.
First identification: A, B.
Second identification: A, C, D.
Melts between 68°C and 71°C.
The infrared absorption spectrum is concordant with the reference spectrum of Ethyl paraben or with the spectrum obtained from Ethyl paraben CRS.
Examine the chromatograms obtained in the test for related substances. The principle spot in the chromatogram obtained with test solution (b) is similar in position and size to the principle spot in the chromatogram obtained with reference solution (b).
To about 10 mg in a test tube add 1 ml of sodium carbonate solution, heat to boiling for 30 seconds and cool (solution A) to a further 10mg in a test tube add 1 ml of sodium carbonate solution, the substance partly dissolves (solution B). Add at the same time to each of solutions A and B 5 ml of aminopyrazolone solution R and 1 ml of potassium ferricyanide solution R and mix. Solution B is yellow to orange brown. Solution A is orange to Red and the colour is clearly more intense than any similar colour that may be obtained with solution B.
Appearance of solution
A 10% w/v solution in ethanol (95%) is clear and not more intensely coloured than reference solution prepared by mixing 1.5 ml ferric chloride colorimetric solution, 0.8 ml cobaltous chloride colorimetric solution, 0.2 ml cupric sulphate colorimetric solution and 97.5 ml of 1% w/v HCl solution.
Dissolve 1.0 g in sufficient ethanol (95%) to produce 10 ml. To 2 ml of the solution add 3 ml of alcohol R, 5 ml of carbon dioxide-free water and 0.1 ml of bromocresol green solution R. Not more than 0.1ml of 0.1M sodium hydroxide is required to change the colour of the solution to blue.