A white, crystalline powder, odourless or almost odourless; hygroscopic.
2.
Solubility
Freely soluble in water and in ethanol (50%), sparingly soluble in ethanol (95%), practically in soluble in fixed oils.
3.
Identifiction
A. Dissolve 0.5 gm in 5 ml of water and acidify to litmus paper with hydrochloric acid; a white precipitate is produced. Wash the precipitate with water and dry. The infrared absorption spectrum of the precipitate, appendix 5.4 is concordant with the reference spectrum of Propyl Paraben or with the spectrum obtained from Propyl Paraben RS.
B. The precipitate obtained in test A on ignition gives the reactions of sodium salts, appendix 3.1
4.
PH
Between 9.5 to 10.5, determined in a 0.1% w/v solution, appendix 8.11
5.
Appearance of solution
A 10% solution in water is clear, 10% solution in water is clear, or not more opalescence than Opalescence standard OS1 prepared by 5.0 ml of Opalescence standard & 95 ml of water .
