Zinc Acetate

Basic Information

Name: Zinc Acetate

CAS No: Zinc acetate dihydrate [5970-45-6] , Zinc acetate anhydrous [557-34-6]

Functional Categories

Emollient Emulsion stabilizer Gelling agent Opacifier Stabilizing agent

1. Nonproprietary Names

BP: Zinc Acetate PhEur: Zinc Acetate Dihydrate USP: Zinc Acetate

2. Synonyms

Acetic acid, zinc salt; dicarbomethoxy zinc; zinc acetas dihydricus; zinc (II) acetate; zinc diacetate; zinc ethanoate.

3. Chemical Name & CAS Registry

Zinc acetate dihydrate [5970-45-6] , Zinc acetate anhydrous [557-34-6]

4. Empirical Formula & Molecular Weight

C4H6O4Zn2H2O , 219.50 (for dihydrate) C4H6O4Zn ,183.47(for anhydrous)

5. Structural Formula

6. Applications

Zinc acetate has been used as an excipient in a variety of pharmaceutical formulations including topical gels, lotions, and solutions, and subcutaneous injections. It has also been investigated for use in an oral controlled-release formulation for water-soluble drugs in combination with sodium alginate and xanthan gum.(1) Therapeutically, zinc acetate has been used in oral capsules for the treatment of Wilson’s disease.(2,3) Zinc acetate has also been demonstrated to be effective as a spermicide in vaginal contraceptives.(4

7. Description

Zinc acetate occurs as white crystalline, lustrous plates with a faint acetic odor and an astringent taste.

8. Pharmacopeial Specifications

See Table I.

9. Typical Properties

Acidity/alkalinity pH = 6.0–8.0 (5% w/v aqueous solution of the dihydrate) Boiling point Decomposes. Melting point 2378C Solubility For the dihydrate, see Table II. Specific gravity 1.735

10. Stability & Storage

Zinc acetate loses water of hydration above 1008C. Zinc acetate should be stored in an airtight container in a cool, dry, place.

11. Incompatibilities

Zinc acetate is incompatible with oxidizing agents, zinc salts, alkalis and their carbonates, oxalates, phosphates, and sulfides.(5)

12. Method of Manufacture

Zinc acetate is synthesized by reacting zinc oxide with glacial acetic acid, with subsequent crystallization, separation by centrifugation, and drying and milling of the crystals. No organic solvents are used during the synthesis.

13. Safety

Zinc acetate is used in topical pharmaceutical formulations and subcutaneous injections, where it is generally regarded as relatively nontoxic and nonirritant when used as an excipient. However, zinc acetate is poisonous by intravenous and intraperitoneal routes; it is also moderately toxic following oral consumption.(5) Zinc acetate: LD50 (rat, oral): 2.510 g/kg(5) LD50 (mouse, IP): 0.057 g/kg Zinc acetate dihydrate: LD50 (mouse, IP): 0.108 g/kg LD50 (mouse, oral): 0.287 g/kg LD50 (rat, IP): 0.162 g/kg LD50 (rat, oral): 0.794 g/kg

14. Handling Precautions

Observe normal precautions appropriate to the circumstances and quantity of material handled. Eye protection and gloves are recommended. When heated to decomposition, zinc acetate emits toxic fumes of zinc oxide.

15. Regulatory Status

Included in the FDA Inactive Ingredients Database (SC injections; topical lotions and solutions). Included in medicines licensed in the UK.

16. Related Substances

17. Comments

A specification for zinc acetate is included in the Japanese Pharmaceutical Excipients (JPE).(6) Proprietary names for zinc acetate include Galzin (Teva Pharmaceuticals) and Wilzin (Orphan Europe (UK) Ltd). The EINECS number for zinc acetate is 209-170-2.