PARAMETERS

USP

STANDARD

RESULT

REMARKS

Description

Colorless, odorless scales of a somewhat pearly luster, or crystals, or white powder that is slightly unctuous to the touch. Is stable in the air.

Solubility

Soluble in water, and in alcohol; freely soluble in glycerin, in boiling water, and in boiling alcohol?

Solubility in alcohol

One gram dissolves completely in 10 ml of boiling alcohol

Completeness of solution

One gram dissolves in 25 ml of water, producing a clear solution

Identification

It responds to the test for borate <191>

Loss on drying <731>

It loses not more than 0.5% of its weight

Heavy metals Method I <231>

The limit is 0.002%

Assay

Contains not less than 99.5% and not more than 100.5% of H₃BO₃, calculated on the dried basis