Composition n-propyl 3,4,5 – trihydroxybenzoate.
Empirical Formula C₁₀H₁₂O₅
Formula Weight 212.20
Pharmacopoeia status BP/Eur Ph. /USP
Appearance white – cream crystalline powder.
Solubility Very slightly soluble in water, freely soluble in ethanol and ether. Alkali soluble.

Identification:
A. Melting Point 148 oC – 151 oC.
B. infrared spectrum conforms to reference standard.
C. TLC conforms to reference standard chromatogram.
D. yellow precipitate with bismuth subnitrate solution.
E. (USP) UV absorption conforms to reference standard.

Appearance of Solution 5% solution in ethanol is clear and not more coloured than reference standard solution BY5 (Ph EUR Method II 2.2.2)