Understanding of mannitol: 1, mannitol in the clinic is a good diuretic, reduce intracranial pressure, intraocular pressure and treatment of renal drugs, dehydrating agents, sugar substitutes. 2, as a tablet with excipient, mannitol non-hygroscopic, fast drying, chemical stability, and has a crisp, good granulation, etc., used for most tablets of anticancer drugs, antibacterial drugs, antihistamines and vitamins. In addition, it is also used in chewable tablets such as sobriety medicine and mouth coolant. 3, in terms of food, the product in the sugar and sugar alcohols in the minimum water absorption, and has a refreshing sweetness, used for maltose, chewing gum, rice cakes and other food products such as anti-adhesion, as well as used as a general confectionery anti-adhesion powder. 4, used as food for diabetics, bodybuilding food and other low-calorie, low-sugar sweeteners. 5, in industry, mannitol can be used in the plastics industry, the system of rosin acid ester and margarine resin, explosives, detonators (nitro-mannitol) and so on. 6, in chemical analysis for the determination of boron, biological testing used as a bacterial culture agent. Physicochemical properties of mannitol: 1, 20% of mannitol is a six-carbon polyol, its molecular weight is 163, three times that of urea, PH value of 5-7 2, white needle-like crystals, 1g can be dissolved in about 5.5ml of water (20 ℃), more soluble in hot water, low temperature is often precipitated, commonly used in 80-degree water to dissolve the water before use. The aqueous solution is alkaline. The product is an isomerization of sorbitol, but there is no hygroscopicity at all. Mannitol has a sweet flavor, and its sweetness is equivalent to 70% of sucrose. 3, mannitol can be extracted from kelp, can also be extracted from seaweed, but more often used glucose or sucrose solution electrolytic reduction or catalytic reduction method. Pharmacological properties of mannitol: 1, for high osmotic dehydration. 1g mannitol can produce osmotic concentration of 5.5mOsm, injection of 100g mannitol can make 2000ml intracellular water transfer to the outside of the cell, urinary excretion of sodium 50g. 2, mannitol is a monosaccharide, not metabolized in vivo, after glomerular filtration in the tubules of the kidneys are very little reabsorption, osmotic diuresis. 3, about 3% of the total volume, the total volume of the total volume of the total volume of the total volume of the total volume of the total volume of the total volume of the total. 3.About 3% of the total amount is converted into glycogen in the liver, 97% is rapidly filtered through the glomerulus. 4, in the intravenous injection within 20 minutes after the effect, 2-3 hours of antihypertensive effect reached a peak, can be maintained for 4-6 hours. 5, Mannitol can cross the placental barrier. It should be used with caution in pregnant women. 6, Mannitol oral absorption is very little. Although mannitol can be absorbed by the human stomach and intestines, but in the body does not accumulate. After being absorbed, part of the body is metabolized, the other part of the urinary excretion; by hydrobromic acid reaction can be produced dibromomannitol. Intravenous injection rapidly into the extracellular fluid without entering the cell. However, when the blood mannitol concentration is very high or the existence of acidosis, mannitol can pass the blood-brain barrier and cause intracranial pressure rebound. The diuretic effect appears 1 hour after sedation and is maintained for 3 hours. The effect of lowering intraocular pressure and intracranial pressure appears within 15 minutes after sedation, peaks at 30 to 60 minutes, and is maintained for 3 to 8 hours. Glycogen can be produced by the liver, but the amount metabolized by the liver is usually small because of rapid renal excretion after intravenous injection. The T1/2 of this drug is 100 minutes and may be extended to 6 hours when acute renal failure is present. When renal function is normal, 100 g of mannitol is injected intravenously and 80% is excreted via the kidneys within 3 hours.