Methyl Paraben

No.

Test

Specification

Observations

1.

Appearance

White or almost white, hygroscopic crystalline Powder

White, hygroscopic crystalline powder

2.

Solubility

Freely Soluble in water, sparingly soluble in ethanol (96 per cent), practically insoluble in methylene chloride.

Freely soluble in water, sparingly soluble insoluble in methylene chloride.

3.

Identification

B) IR

The infrared absorption spectrum of the sample should be concordant with the spectrum of methyl parahydroxybenzoate CRS.

Passes

D) Reaction of Solution

Passes the test

Passes

4.

Appearance of Solution

A 10 % w/v Solution in carbon dioxide-free water clear and not more intensely coloured than BY 6. (Determined on 5.0 gm)

Complies.

5.

PH

9.5 to 10.5

9.63

6.

Related substances by HPLC

Impurity A: Impurities: Not more than 3.0%

1.79%

Unspecified  impurities: Not more than 0.5 %

Not Detected.

Sum of impurities  Other than A: not more than 1.0 %

No Detected.

7.

Chloride

Maximum 350 ppm.

Less than 350 ppm

8.

Sulphate

Maximum 300 ppm.

Less than 300 ppm

9.

Heavy metals

Maximum 10 ppm.

Less than 10 ppm

10.

Water

Maximum 5.0 % Determined on 0.500 gm.

1.12 %

11.

Assay by HPLC (as C8H7NaO3)

95.0 % to 102.0 %

97.17 %