Packaging and storage—
Preserve in suitable collapsible ophthalmic ointment tubes.
Appearance—
Transfer a portion of it to a suitable test tube, and examine the sample in front of a light source: the sample should appear translucent.
Color—
Examine the extruded ointment for color: it is colorless to light yellow.
Sterility 
71
—
It meets the requirements when tested as directed for
Membrane Filtration under
Test for Sterility of the Product to be Examined.
Homogeneity—
Transfer about 250 mg of it to a clean microscope slide and examine for separation: no oily or watery substances should be visibly separated from the ointment. Place a cover slip on the ointment and flatten until light readily passes through the sample. Examine for agglomeration: no solid particles are visible.
Acidity or alkalinity—
Transfer 20.0 g of it to a 400-mL beaker, add 100 mL of a 1 in 2 mixture of neutralized alcohol and water, agitate thoroughly, and gradually heat to boiling. Boil for 10 minutes. Add 1 mL of phenolphthalein TS and rapidly titrate, with vigorous agitation, with either 0.1 N sodium hydroxide VS (from a colorless alcohol-water layer to a sharp pink endpoint) or 0.1 N hydrochloric acid VS (from a pink alcohol-water layer to a colorless endpoint): not more than 0.40 mL of 0.1 N titrant is required.
