Calcium Lactate

Basic Information

Name: Calcium Lactate

CAS No: Calcium lactate anhydrous [814-80-2] Calcium lactate monohydrate and trihydrate [41372-22-9] Calcium lactate pentahydrate [5743-47-5] and [63690-56-2]

Functional Categories

Antimicrobial preservative Buffering agent Crosslinking agent Tablet and capsule diluent Tablet binder Tablet filler Therapeutic agent Thickening agent

1. Nonproprietary Names

BP: Calcium Lactate Pentahydrate JP: Calcium Lactate Hydrate PhEur: Calcium Lactate Pentahydrate USP: Calcium Lactate

2. Synonyms

Calcii lactas pentahydricus; calcium bis(2-hydroxypropanoate) pentahydrate; calcium dilactate; calcium lactate (1:2) hydrate; calcium lactate (1:2) pentahydrate; E327; 2-hydroxypropanoic acid, calcium salt; lactic acid, calcium salt; mixture of calcium (2R)-, (2S)- and (2RS)-2-hydroxypropanoates pentahydrates; propanoic acid, 2-hydroxy-, calcium salt (2:1), hydrate; Puracal

3. Chemical Name & CAS Registry

Calcium lactate anhydrous [814-80-2] Calcium lactate monohydrate and trihydrate [41372-22-9] Calcium lactate pentahydrate [5743-47-5] and [63690-56-2]

4. Empirical Formula & Molecular Weight

C6H10CaO6 218.2 (anhydrous) C6H10CaO6H2O 236.0 (monohydrate) C6H10CaO63H2O 272.3 (trihydrate) C6H10CaO65H2O 308.3 (pentahydrate)

5. Structural Formula

6. Applications

Calcium lactate is used as a bioavailability enhancer and nutrient supplement in pharmaceutical formulations. A spray-dried grade of calcium lactate pentahydrate has been used as a tablet diluent in direct compression systems,(1) and has been shown to have good compactability. The properties of the pentahydrate form have been considered superior to those of calcium lactate trihydrate when used in direct compression tablet formulations.(2) Tablet properties may be affected by the hydration state of the calcium lactate and particle size of the material: reducing particle size increased crushing strength, whereas storage of tablets at elevated temperature resulted in dehydration accompanied by a reduction in crushing strength.(3) Calcium lactate has also been used as the source of calcium ions in the preparation of calcium alginate microspheres for controlled-release delivery of active agents. It has been shown to result in lower calcium concentrations in the finished microspheres when compared with calcium acetate.(4) Therapeutically, calcium lactate has been used in preparations for the treatment of calcium deficiency

7. Description

Calcium lactate occurs as white or almost white, crystalline or granular powder. It is slightly efflorescent.

8. Pharmacopeial Specifications

See Table I. See also Section 18.

9. Typical Properties

Acidity/alkalinity pH = 6.0–8.5 for a 10% aqueous solution for Puracal PP(8) Density (bulk) 0.56 g/cm3(2); 0.3–0.5 g/cm3 for Puracal PP(5) Density (tapped) 0.67 g/cm3(2) Density (true) 1.494 g/cm3(2) Hygroscopicity The pentahydrate form is nonhygroscopic (see Section 11). Melting point >2008C for Puracal PP(5) Solubility Soluble in water, freely soluble in boiling water; very slightly soluble in ethanol (95%).

10. Stability & Storage

Calcium lactate can exist in a number of hydration states, which are characterized as anhydrous, monohydrate, trihydrate, and pentahydrate. Dehydration of the pentahydrate form is rapid at temperatures of 558C and above. Dehydration is reported to be accompanied by some loss of crystallinity.(6) Tablet crushing strength was reported to be reduced following dehydration of calcium lactate pentahydrate.(3)

11. Incompatibilities

Calcium salts, including the lactate, can display physical incompatibility with phosphate in the diet or therapeutic preparations, for example in enteral feed mixtures.(7

12. Method of Manufacture

Calcium lactate is prepared commercially by neutralization with calcium carbonate or calcium hydroxide of lactic acid obtained from fermentation of dextrose, molasses, starch, sugar, or whey.(8)

13. Safety

Calcium lactate was found to have no toxic or carcinogenic effects when dosed at levels of 0%, 2.5%, and 5% in drinking water to male and female rats for 2 years.(9)

14. Handling Precautions

Observe normal precautions appropriate to the circumstances and quantity of the material handled.

15. Regulatory Status

GRAS listed except for infant foods/formulas.(10) Accepted as a food additive in Europe. Calcium lactate (anhydrous) is included in the FDA Inactive Ingredients Database (vaginal, tablet). It is used in oral dosage forms. Included in vaginal pessary formulations licensed in the UK.

16. Related Substances

Lactic acid; sodium lactate.

17. Comments

Calcium lactate is available in a number of grades with respect to hydration state, purity, and particle size. Care should be taken to understand the hydration state of the material in use. The USP 32 states that on product labeling, ‘calcium lactate’ should be understood as an amount of calcium equivalent to that contained in the stated amount of calcium lactate pentahydrate. Each 1.0 g of calcium lactate pentahydrate contains 130 mg (3.2 mmol) of calcium. The use of calcium lactate in film coatings as an alternative white pigment to titanium dioxide has been reported.(11) The white coloration may be due to interactions between the hypromellose polymer and calcium ions in the film. The use of films containing calcium lactate as edible coatings for food products has also been reported. Milk proteins have been used as the film former, crosslinked by the calcium salt.(12) Lactate salts, including calcium lactate, have been reported as having antimicrobial properties and have been applied as preservatives in foods.(13) The USP 32 monograph for calcium lactate covers the anhydrous and hydrous forms. The PhEur 6.0 lists separate monographs for calcium lactate, anhydrous, calcium lactate monohydrate, calcium lactate pentahydrate, and calcium lactate trihydrate. The calcium in calcium lactate is bioavailable when administered orally; there are monographs for calcium lactate tablets in both BP 2009 and USP 32. A specification for calcium lactate is contained in the Food Chemicals Codex (FCC).(14) The EINECS number for anhydrous calcium lactate is 212-406- 7. The PubChem Compound ID (CID) for anhydrous calcium lactate is 521805 and for calcium lactate pentahydrate it is 165341