(+)-Lactose

50 to 100 mg/mL at 68 °F (NTP, 1992)

195000

Insoluble in ether and chloroform; very slightly soluble in alcohol

In water, 1.95X10+6 mg/L at 20 °C

433 °F (NTP, 1992)

201-202 °C

Decomposes at 203.5 °C

White powder; MP: 222.8 °C; very soluble in water; slightly soluble in ethanol; insoluble in ethyl ether, chloroform /alpha-Lactose/

Somewhat sweeter than the alpha-form. Specific optical rotation +34 deg (3 minutes) to +39 deg (6 minutes) to +46 deg (1 hour) to 52.3 deg (22 hours) at 25 °C/D. One gram dissolves in 2.2 mL water at 15 °C, in 1.1 mL boiling water. After a few days crystals of the less soluble alpha-monohydrate appear from saturated solutions. /beta-Lactose/

Lactose is a white hard crystalline powder. (NTP, 1992)

White solid; [CAMEO]

Stable in air

On hydrolysis with 2% H2So4, or with emulsin lactose yields 1 mol d_glucose and 1 mol D-galactose. Reduces Fehling's solution

MP: 254 °C; density: 1.59 g/cu cm at 20 °C; very soluble in water; slightly soluble in ethanol; insoluble in ethyl ether, chloroform /beta-D-Lactose/

MP: 201 °C (decomposes); density: 1.547 g/cu cm at 20 °C; very soluble in water; insoluble in ethanol, ethyl ether, chloroform, methanol /alpha-lactose monohydrate/

Monoclinic sphenoidal crystals from water. Faintly sweet taste. Stable in air, but readily absorbs odors. Becomes anhydrous at 120 °C; mp: 201-202 °C (rapid heating). Shows mutarotation. Specific optical rotation +92.6 deg to +83.5 deg (10 minutes) to +69 deg (50 minutes) to 52.3 deg (22 hours, c = 4.5) at 20 °C/D. ... One gram dissolves in 5 mL water, in 2.6 mL boiling water; very slightly soluble in alcohol; insoluble in chloroform, ether. Ka at 16.5 °C = 6.0X10-13. Specific gravity of aqueous solutions calculated for the monohydrate: 5.2% = 1.018; 10.2% = 1.038; 20.0% = 1.078; 30.2% = 1.123; 50.9% = 1.226; 60.8% = 1.281; 69.1% = 1.330 at 20 °C/4 °C /alpha-Lactose monohydrate/

This chemical does not meet GHS hazard criteria for 99.6% (263 of 264) of all reports.

Not Classified；Reported as not meeting GHS hazard criteria by 263 of 264 companies (only 0.4% companies provided GHS information). For more detailed information, please visit ECHA C&L website.

Aggregated GHS information provided per 264 reports by companies from 3 notifications to the ECHA C&L Inventory.；Reported as not meeting GHS hazard criteria per 263 of 264 reports by companies.；There is 1 notification provided by 1 of 264 reports by companies with hazard statement code(s).；Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

Chemical: D-Glucose, 4-O-.beta.-D-galactopyranosyl-

Chemical: D-Glucose, 4-O-.beta.-D-galactopyranosyl-, monohydrate

Lactose: Does not have an individual approval but may be used under an appropriate group standard

Lactose monohydrate: Does not have an individual approval but may be used under an appropriate group standard

IMAP assessments - D-Glucose, 4-O-.beta.-D-galactopyranosyl-, monohydrate: Human health tier I assessment

IMAP assessments - D-Glucose, 4-O-.beta.-D-galactopyranosyl-: Human health tier I assessment；Evaluation - Chemicals that are unlikely to require further regulation to manage risks to environment

Requirements of specific standardized sweeteners and table sirups. ... (a) Lactose is the carbohydrate normally obtained from whey. It may be anhydrous or contain one molecule of water of crystallization or be a mixture of both forms. (b) The food shall meet the following specifications: (1) The lactose content is not less than 98.0 percent, mass over mass (m/m), calculated on a dry basis. (2) The sulfated ash content is not more than 0.3 percent, m/m, calculated on a dry basis. (3) The pH of a 10.0-percent m/m solution is not less than 4.5 nor more than 7.5. (4) The loss on drying for 16 hours at 120 °C is not more than 6.0 percent, m/m. (c) The name of the food is "Lactose" or, alternatively, "Milk sugar".

Drug products containing certain active ingredients offered over-the-counter (OTC) for certain uses. A number of active ingredients have been present in OTC drug products for various uses, as described below. However, based on evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients for the specified uses: lactose is included in digestive aid drug products.

Drug products containing certain active ingredients offered over-the-counter (OTC) for certain uses. A number of active ingredients have been present in OTC drug products for various uses, as described below. However, based on evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients for the specified uses: lactose is included in weight control drug products.

Flammable and/or toxic gases are generated by the combination of alcohols with alkali metals, nitrides, and strong reducing agents. They react with oxoacids and carboxylic acids to form esters plus water. Oxidizing agents convert them to aldehydes or ketones. Alcohols exhibit both weak acid and weak base behavior. They may initiate the polymerization of isocyanates and epoxides.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. If symptoms (such as redness or irritation) develop, immediately transport the victim to a hospital.；SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.；INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.；INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

Water spray, dry chemical, carbon dioxide, or foam as appropriate for surrounding fire and materials.

This material is assumed to be combustible. As with all dry powders, it is advisable to ground mechanical equipment in contact with dry material to dissipate the potential buildup of static electricity. Mixtures with oxidants (e.g., potassium chlorate, potassium nitrate, or potassium perchlorate) may be explosion hazards.

Wear approved respiratory protection, chemically compatible gloves, and protective clothing. Wipe up spillage or collect spillage using a high-efficiency vacuum cleaner. Avoid breathing dust. Place spillage in appropriately labeled container for disposal. Wash spill site.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, you should dampen the solid spill material with water, then transfer the dampened material to a suitable container. Use absorbent paper dampened with water to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.；STORAGE PRECAUTIONS: You should store this material in a refrigerator. (NTP, 1992)

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

As with all fires, evacuate personnel to a safe area. Firefighters should use self-contained breathing equipment and protective clothing.

As a general rule, when handling USP Reference Standards, avoid all contact and inhalation of dust, mists, and/or vapors associated with the material. Clean equipment and work surfaces with suitable detergent or solvent after use. After removing gloves, wash hands and other exposed skin thoroughly.

Chemically compatible. For handling solutions, ensure that the glove material is protective against the solvent being used. Use handling practices that minimize direct hand contact. Employees who are sensitive to natural rubber (latex) should use nitrile or other synthetic nonlatex gloves. Use of powdered latex gloves should be avoided due to the risk of latex allergy.

Safety glasses with sideshields are recommended. Face shields or goggles may be required if splash potential exists or if corrosive materials are present. Approved eye protection (e.g., bearing the ANSI Z87 or CSA stamp) is preferred. Maintain eyewash facilities in the work area.

For handling of laboratory scale quantities, a cloth lab coat is recommended. Where significant quantities are handled, work clothing may be necessary to prevent take-home contamination.

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)

Airborne exposure should be controlled primarily by engineering controls such as general dilution ventilation, local exhaust ventilation, or process enclosure. Local exhaust ventilation is generally preferred to general exhaust because it can control the contaminant at its source, preventing dispersion into the work area. An industrial hygiene survey involving air monitoring may be used to determine the effectiveness of engineering controls. Effectiveness of engineering controls intended for use with highly potent materials should be assessed by use of nontoxic surrogate materials.

Where respirators are deemed necessary to reduce or control occupational exposures, use NIOSH-approved respiratory protection and have an effective respirator program in place (applicable U.S. regulation OSHA 29 CFR 1910.134).

Rats fed diets containing 40% lactose for 5 days exhibited higher total liver cholesterol values than controls fed a basal sucrose diet. Lactose-supplemented diets markedly reduced the formation of coprostanol, suggesting a possible relationship between this finding and cholesterol absorption. Quantitative balance studies demonstrated the absorption of 40.4% of administered cholesterol by sucrose controls in contrast to 66.2% of the same dose by lactose-fed rats. Both 2% and 4% calcium chloride inhibited cholesterol absorption when the diet was supplemented with lactose, while as much as 4 % calcium chloride was required to produce a similar effect on a sucrose diet...

/HUMAN EXPOSURE STUDIES/ /Researchers/ studied the tolerance of nine lactose malabsorbing children (mean age 10, range 9-16) via the feeding of 500 mL of conventional or lactose hydrolyzed milk, with no effort to disguise taste differences. Symptoms of abdominal pain, flatulence, and diarrhea were very significantly greater after ingestion of the nonhydrolyzed milk. Thus, clear-cut lactose intolerance to a 25 gram dose of lactose was observed in these nine children. On a lactose dosage per kg body weight basis, the 25 gram dose to 10 year olds was roughly equivalent to a 50 gram dose for middle age adult subjects.

/HUMAN EXPOSURE STUDIES/ /Researchers/ studied 97 lactose malabsorbing, healthy adult Mexican subjects. The subjects received 250 ml of milks containing 0 grams, 12.5 grams, and 37.5 grams of lactose, with taste difference disguised with chocolate. Compared to the lactose free preparation, the 12.5 gram dose induced a highly significant increase in symptoms (16 percent were severe) and the 37.5 gram dose resulted in very severe symptoms in 71 percent of subjects. This is the only study using multiple dosages of lactose in which appreciable symptoms were observed with 12 grams of lactose.

/HUMAN EXPOSURE STUDIES/ /Researchers/ tested 35 well nourished Latin American malabsorbers with 250 mL or 500 mL of lactose-containing and a low lactose milk from which 86 percent of the lactose had been removed. The products were said to be similar in taste and consistency. Doses of lactose fed (with a light breakfast) were 1.6 grams (250 mL, lactose- reduced milk), 3.2 grams (500 mL, lactose reduced milk), 11.3 grams (250 mL milk), 22.5 grams (500 mL milk), and 50 grams (lactose tolerance test). The respective median symptom scores for these lactose loads were 0.3, 0.2, 0.5, 1.1, and 6.1, with a maximal score of 12. No significant increase in symptoms was noted between conventional and low lactose milk at the 250 mL dosage, while a significant increase was noted with the 500 mL dosage, although symptoms tended to be slight (score 1.1 out of 12). When the lactose dosage was increased to 50 grams (1,000 mL of milk), symptoms became appreciable (score 6.1 out of 12), although there was no control for this phase of the study. This study demonstrates that 11.3 grams of lactose was tolerated, 22.5 grams yielded mild symptoms, and 50 grams was clearly intolerable.

/HUMAN EXPOSURE STUDIES/ /Investigators/ fed 13 healthy adult lactose malabsorbers varying dosages of lactose (0 to 20 grams) in water without other food. Authors masked taste differences with aspartame. A statistically significant increase in symptoms was observed when the dose of lactose reached 20 grams, although mean symptom severity score was less than "slight." Results suggest that the ability of lactose malabsorbers to ingest lactose without detectable symptoms occurs between a 12 gram and 20 gram dosage of lactose when the sugar is administered in water without other food.

For more Human Toxicity Excerpts (Complete) data for Lactose (9 total), please visit the HSDB record page.

Drug-Induced Liver Injury Severity and Toxicity (DILIst)

lactose

DILI Negative

Oral

DOI:10.1016/j.drudis.2019.09.022

/LABORATORY ANIMALS: Acute Exposure/ ...The purpose of this work was to investigate the safety of lactose and chitosan to the pulmonary tissue when delivered by inhalation. The study was carried out with 18 Wistar rats divided in three groups receiving distilled water, lactose or chitosan. A solution of each excipient was administered by inhalation at a dose of 20 mg. The lungs were excised and processed to determine several biochemical parameters used as toxicity biomarkers. Protein and carbonyl group content, lipid peroxidation, reduced and oxidized glutathione (GSSG), myeloperoxidase (MPO), cooper/zinc and manganese superoxide dismutase, catalase, glutathione S-transferase and glutathione peroxidase were determined. Results of myeloperoxidase activity and glutathione disulfide lung concentrations showed a relevant decrease for chitosan group compared to control: 4.67 +/- 2.27 versus 15.10 +/- 7.27 (P = 0.011) for MPO and 0.89 +/- 0.68 versus 2.02 +/- 0.22 (P = 0.014) for GSSG. The other parameters did not vary significantly among groups. Lactose and chitosan administered by inhalation failed to show toxic effects to the pulmonary tissue. A protective effect against oxidative stress might even be attributed to chitosan, since some biomarkers had values significantly lower than those observed in the control group when this product was inhaled. Nevertheless, caution must be taken regarding chemical composition and technological processes applied to incorporate these products during drug formulation, in particular for dry powder inhalators.

/LABORATORY ANIMALS: Acute Exposure/ Weanling or adult (9 wk old) rats were fed diets containing 0, 250 or 500 g lactose/kg for 10 days, after which the activities of six cecal microbial enzymes (azoreductase, beta-glucosidase, beta-glucuronidase, nitrate reductase, nitroreductase and urease) were determined. Adult controls had larger ceca than weanlings, but the numbers of bacteria were not significantly different. Expressed in relation to body weight, cecal microbial enzyme activities were significantly lower in adult controls, with the exceptions of beta-glucuronidase and urease. Lactose caused cecal enlargement; this was greatest in weanling animals, which also showed a decreased concentration of bacteria. Lactose increased total nitrate reductase and urease activities in both age groups, but decreased total azoreductase and nitroreductase activities in weanlings. Enzyme activities per 1x10+9 bacteria were decreased for azoreductase, beta-glucosidase, beta-glucuronidase and nitroreductase in both age groups, while urease activity increased. Azoreductase and nitroreductase activities were highly correlated but nitrate reductase and urease did not correlate significantly with any other enzyme activity.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ .../The study/ investigated the metabolic effects of high lactose diets in Long-Evans female rats. Seventy-five Long-Evans female rats (25-day-old) were randomized to receive one of 3 diets for 7 months: glucose diet (CON); low lactose diet (10.5%, LLD); or a high lactose diet (41.9%, HLD). Necropsy was performed seven months after randomization. HLD animals had significantly lower body weights than controls (P < 0.01). These animals continued to grow, however at a retarded rate compared to the CON group. The HLD group also had significantly lower triglyceride and non-esterified fatty acid levels than the CON group (P < 0.01 and P < 0.05). Serum glucose concentrations were lower in the HLD group compared to CON animals (P < 0.05), while serum insulin levels were lower than both the LLD and CON animals (P < 0.01 and P < 0.05). Leptin exhibited a similar trend. Thyroid studies revealed no difference in /thyroid-stimulating hormone/ between groups. Free /thyroxine/ was significantly higher in HLD rats compared to LLD and CON rats while free /triiodothyronine/ was lower in the HLD group (P < 0.05). This indicates a possible impairment in /thyroxine/ to /triiodothyronine/ conversion. ... data suggests that a long-term high lactose diet is associated with a decrease in insulin and leptin levels, and an increase in the insulin to glucose ratio. However, these changes are seen in the presence of a decreased body mass. A significant effect on thyroid hormone metabolism is also seen, and may be an adaptive mechanism in lactose-fed rats.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Chronic consumption by rats of diets rich in sugars or sugar alcohols leads to an increased incidence of pheochromocytomas. This relationship is hypothesized to be based on altered Ca(2+) homeostasis due to increased intestinal Ca(2+) absorption. Other agents associated with pheochromocytomas in rats in long-term toxicity studies have been shown to increase chromaffin cell proliferation, leading to the suggestion that the tumors occur secondarily to increased chromaffin cell turnover. We have demonstrated marked stimulation of chromaffin cell proliferation by vitamin D3, a potent stimulus to Ca(2+) absorption not previously associated with adrenal medullary toxicity. This effect is detectable during the first week of dietary supplementation and persists throughout a 4-week time course. Lactose and xylitol, representative of sugars and sugar alcohols associated with pheochromocytomas, are also mitogenic but to a lesser extent, with their effects first detectable during Week 4 of dietary supplementation. Vitamin D 3, its active metabolite calcitriol, lactose, and xylitol all fail to stimulate proliferation of rat chromaffin cellsin vitro.The mitogenic effects of these agents may be mediated presynaptically in vivo.The data suggest that altered Ca (2+) homeostasis may increase chromaffin cell proliferation and support the hypothesis that diets containing high concentrations of sugars and sugar alcohols cause pheochromocytomas in rats secondarily by this mechanism.

For more Non-Human Toxicity Excerpts (Complete) data for Lactose (10 total), please visit the HSDB record page.

NIOSH (NOES Survey 1981-1983) has statistically estimated that 132,323 workers (76,197 of these were female) were potentially exposed to lactose in the US(1). NIOSH (NOES Survey 1981-1983) has statistically estimated that 1,297 workers (922 of these were female) were potentially exposed to lactose powder in the US(1). Occupational exposure to lactose may occur through inhalation and dermal contact with this compound at workplaces where lactose is produced or used. Monitoring and use data indicate that the general population may be exposed to lactose via ingestion of and dermal contact with this natural compound and consumer products containing lactose(SRC).

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/

/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/

/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

Chemical: D-Glucose, 4-O-.beta.-D-galactopyranosyl-

Chemical: D-Glucose, 4-O-.beta.-D-galactopyranosyl-, monohydrate

Lactose: Does not have an individual approval but may be used under an appropriate group standard

Lactose monohydrate: Does not have an individual approval but may be used under an appropriate group standard

Requirements of specific standardized sweeteners and table sirups. ... (a) Lactose is the carbohydrate normally obtained from whey. It may be anhydrous or contain one molecule of water of crystallization or be a mixture of both forms. (b) The food shall meet the following specifications: (1) The lactose content is not less than 98.0 percent, mass over mass (m/m), calculated on a dry basis. (2) The sulfated ash content is not more than 0.3 percent, m/m, calculated on a dry basis. (3) The pH of a 10.0-percent m/m solution is not less than 4.5 nor more than 7.5. (4) The loss on drying for 16 hours at 120 °C is not more than 6.0 percent, m/m. (c) The name of the food is "Lactose" or, alternatively, "Milk sugar".

Drug products containing certain active ingredients offered over-the-counter (OTC) for certain uses. A number of active ingredients have been present in OTC drug products for various uses, as described below. However, based on evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients for the specified uses: lactose is included in digestive aid drug products.

Drug products containing certain active ingredients offered over-the-counter (OTC) for certain uses. A number of active ingredients have been present in OTC drug products for various uses, as described below. However, based on evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients for the specified uses: lactose is included in weight control drug products.

CIR ingredient: Lactose

Found in the milk of mammals; Used as a nutrient, pharmaceutic aid, and chromatographic adsorbent; [Merck Index] Used in digestive aids, weight control products, bacteriology, confectionery, and to make margarine, butter, penicillin, yeast, edible protein, and riboflavin; [HSDB] Used as a flavoring agent, formulation aid, lubricant or release agent, nutritive sweetener, malting or fermenting aid, oxidizing or reducing agent, solvent, surface-active agent, and stabilizer or thickener for foods; [FDA] Permitted for use as an inert ingredient in non-food pesticide products; [EPA]

Both forms of lactose are employed, with the alpha-form predominating: as a nutrient in preparing modified milk and food for infants and convalescents ... in baking mixtures. Pharmaceutic aid (tablet and capsule excipient and diluent). To produce lactic acid fermentation in ensilage and food products. As a chromatographic adsorbent in analytical chemistry.

... Lactose is included in digestive aid drug products.

... Lactose is included in weight control drug products.

Bacteriology ... in confectionery; margarine and butter manufacture; manufacture of penicillin, yeast, edible protein, and riboflavin; culture media

The liquid whey (about 6.5% dry matter content) is clarified and concentrated in falling film evaporators to 55 - 65% total solids. Upon cooling, the greater part of the lactose crystallizes as lactose monohydrate. The crystal slurry is transferred to a line of decanters and centrifuges and washed several times. ... After drying, milling and fractionation, yellowish lactose (edible grade) of different particle sizes is obtained. After the washing stage the raw product can be redissolved, treated with activated carbon and recrystallized to refined or pharmaceutical grades of lactose. From 1000 kg liquid whey 32.5 kg lactose and 32.5 kg delactosed whey powder are obtained.

D-Glucose, 4-O-.beta.-D-galactopyranosyl-: ACTIVE

Lactose exists in two anomeric forms: alpha- and beta-lactose, differing only in the relative positions of the hydrogen and the hydroxyl group at the C1-atom of the pyranosidic glucose-part. In aqueous solution lactose consists of 61.5% of beta-pyranose and 38.5% of alpha-pyranose; the equilibrium between both forms is established by mutarotation ... Lactose usually crystallizes in the form of its alpha-lactose monohydrate. The anhydrous form can only be obtained at crystallization temperatures >93 °C. Amorphous lactose, which is quite hygroscopic, is a mixture of alpha- and beta-lactose; it can be obtained by rapid drying methods, e.g., spray drying.

The usual milk sugar and the lactose of pharmacy ... U.S.P. requires specific optical rotation +54.4 to +55.9 ( c = 10) /alpha-Lactose monohydrate/

Compared to sucrose, lactose has about one-sixth the sweetening strength.