Zinc sulfate is an astringent and weak antiseptic.
Zinc sulfate is used in ophthalmic solutions as an astringent for the temporary relief of discomfort from minor eye irritation; the drug usually is used in combination with a vasoconstrictor (e.g., phenylephrine hydrochloride) for this condition.
Zinc sulfate ophthalmic solution (no longer commercially available in the US) has also been used in the treatment of angular conjunctivitis caused by Moraxella lacunata .
Zinc sulfate ophthalmic solution is applied topically to the eye in the form of a solution. To prevent contamination of the solution, patients should be instructed to avoid contacting the tip of the container to any other surface and to tightly close the container after use.
For relief of minor eye irritation, 1 or 2 drops of a zinc sulfate ophthalmic solution in combination with a vasoconstrictor are instilled onto the eye 2-4 times daily. Ophthalmic solutions containing zinc sulfate should generally not be used for self-medication for more than 3 days. Patients should be instructed to contact a physician if relief is not obtained within 3 days, or if redness or irritation persists or increases, since these may be signs or symptoms of a serious ocular condition.
Precautions and Contraindications
Patients using zinc sulfate ophthalmic solutions should be advised to discontinue the drug and consult a physician if ocular pain or visual changes occur, they experience continued ocular redness or irritation, or the condition worsens or persists for more than 3 days.
Zinc sulfate exhibits astringent and weak antiseptic activity. These effects may result from precipitation of protein by the zinc ion. Zinc sulfate produces mild vasodilation in concentrations used in ophthalmic preparations; the drug has no decongestant action. Zinc sulfate exhibits mild astringent activity by precipitating protein and clearing mucus from the outer surface of the eye.
Zinc sulfate is an astringent and weak antiseptic. Zinc sulfate occurs as colorless, transparent prisms, or small needles, or as a granular, crystalline powder. Zinc sulfate is odorless, has an astringent metallic taste, and is efflorescent in dry air. Solutions of zinc sulfate are acid to litmus. Zinc sulfate has solubilities of 1.67 g/mL in water and 0.4 g/mL in glycerin; the drug is insoluble in alcohol. Zinc sulfate is commercially available for ophthalmic use only in combination with other drugs.
Zinc sulfate ophthalmic solutions should be stored in tightly closed containers at temperatures not exceeding 40°C, unless otherwise specified by the manufacturer; freezing should be avoided.
Zinc sulfate forms insoluble sulfates with lead, barium, strontium, and calcium salts and slightly soluble salts with silver or mercury. Precipitation of zinc borate may occur when zinc sulfate and sodium borate are combined; glycerin may prevent precipitation. Zinc sulfate has a dehydrating effect on methylcellulose suspensions causing precipitation of methylcellulose. Acacia and proteins may also be precipitated by zinc sulfate.
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|---|---|---|---|
Ophthalmic | Solution | 0.25% with Naphazoline Hydrochloride 0.012% | Clear Eyes® ACR (viscous) | Prestige |
0.25% with Tetrahydrozoline Hydrochloride 0.05% | Visine® A.C. | Pfizer |
