Mannitol is available in concentrations ranging from 5 to 25%:1(6/06); 4
| Concentration | Osmolarity | Available Sizes |
|---|---|---|
| 5% | 275 mOsm/L | 1000 mL |
| 10% | 550 mOsm/L | 500 and 1000 mL |
| 15% | 825 mOsm/L | 500 mL |
| 20% | 1100 mOsm/L | 250 and 500 mL |
| 25% | 1375 mOsm/L | 50 mL |
pH
Trade Name(s)
Osmitrol
Mannitol is administered by intravenous infusion. An administration set with a filter should be used for infusion solutions containing mannitol 20% or more. The dosage, concentration, and administration rate are dependent on the patient’s condition and response.1(6/06); 4
Mannitol solutions should be stored at controlled room temperature and protected from freezing.1(6/06); 4 The solutions are chemically stable. Mannitol 25% was chemically and physically stable after 5 autoclavings at 250°F for 15 minutes. In addition, no extracts or visible particles from the rubber closures were found.83
Crystallization
In concentrations of 15% or greater, mannitol may crystallize when exposed to low temperatures.1(6/06); 4; 593 Do not use a mannitol solution containing crystals. If such crystallization occurs, the recommended procedure for resolubilization is to heat the mannitol in a dry heat cabinet to 70°C for flexible plastic containers with the overwrap intact or to 80°C for glass containers with vigorous shaking. The use of a water bath is not recommended. Mannitol 25% in glass vials may be autoclaved at 121°C. The solution should cool to body temperature before use.1(6/06); 4
The use of a microwave oven to resolubilize crystallized mannitol in glass ampuls has been suggested. Exposure to microwave radiation followed by shaking satisfactorily resolubilized the crystals in a shorter total time than the water bath and autoclave methods and resulted in no chemical decomposition.694
Unfortunately, the use of microwave radiation to solubilize mannitol crystals is a highly risky undertaking. Explosions of mannitol ampuls during microwave exposure have been reported.695; 697 Such explosions could injure someone as well as ruin the microwave oven. The explosion results from pressure building during the heating of the solution that occurs from the microwave exposure.696; 697
One inventive pharmacist redissolved mannitol crystals using a coffeemaker.1114
As an alternative to resolubilizing techniques, the use of warming chambers to maintain the solutions in a crystal-free condition has been recommended.698; 699; 700 Various chambers have been described, including a wooden cabinet,698 a metal kettle,699 and even a bun warmer.700 Storage temperatures of 35 and 50°C have been utilized.698; 699
A related but differing effect is seen when supersaturated solutions of mannitol are placed in polyvinyl chloride (PVC) bags. Within a few minutes, a heavy white flocculent precipitate forms. The needle-like crystals in mannitol solutions result from slow undisturbed growth. The white flocculent mannitol precipitate results from contact with the PVC surfaces, which act as nuclei for rapid crystallization of small crystals. Attempts to resolubilize the precipitate with the aid of heat are not fruitful because crystallization may recur in a short time.432
For a list of references cited in the text of this monograph, search the monograph titled References.