Assay
To boiling flask
A, as described under
Methoxy Determination 431, pipet a quantity of Ophthalmic Solution, equivalent to 50 mg of methylcellulose. Evaporate on a steam bath to dryness, cool the flask in an ice bath, add the specified amount of hydriodic acid, and proceed as directed under
Methoxy Determination 431. Each mL of 0.1 N sodium thiosulfate is equivalent to 1.753 mg of methylcellulose.