63-42-3

Chemical Properties

white crystals or powder

Uses

A disaccharide sugar present in milk.

Definition

A sugar found in milk. It is a disaccharide composed of glucose and galactose units.

Production Methods

There are two anhydrous forms of lactose: a-lactose and b-lactose. The temperature of crystallization influences the ratio of a- and blactose. The anhydrous forms that are commercially available may exhibit hygroscopicity at high relative humidities. Anhydrous lactose is produced by roller drying a solution of lactose above 93.5°C. The resulting product is then milled and sieved. Two anhydrous a-lactoses can be prepared using special drying techniques: one is unstable and hygroscopic; the other exhibits good compaction properties. However, these materials are not commercially available.

General Description

Pharmaceutical secondary standards for application in quality control, provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.

Air & Water Reactions

Water soluble.

Reactivity Profile

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.

Health Hazard

ACUTE/CHRONIC HAZARDS: Lactose should be considered toxic.

Pharmaceutical Applications

Anhydrous lactose is widely used in direct compression tableting applications, and as a tablet and capsule filler and binder. Anhydrous lactose can be used with moisture-sensitive drugs due to its low moisture content. It may also be used in intravenous injections.

Safety

Lactose is widely used in pharmaceutical formulations as a diluent and filler-binder in oral capsule and tablet formulations. It may also be used in intravenous injections. Adverse reactions to lactose are largely due to lactose intolerance, which occurs in individuals with a deficiency of the intestinal enzyme lactase, and is associated with oral ingestion of amounts well over those found in solid dosage forms.

storage

Mold growth may occur under humid conditions (80% RH and above). Lactose may develop a brown coloration on storage, the reaction being accelerated by warm, damp conditions. At 80°C and 80% RH, tablets containing anhydrous lactose have been shown to expand 1.2 times after one day. Lactose anhydrous should be stored in a well-closed container in a cool, dry place.

Purification Methods

-Lactose crystallises from water below 93.5o as the hydrate which can be dried at 80o/14mm. [Horst Recl Trav Chim, Pays-Bas 72 878 1953, Beilst 17 III/IV 3066.]

Incompatibilities

Lactose anhydrous is incompatible with strong oxidizers. When mixtures containing a hydrophobic leukotriene antagonist and anhydrous lactose or lactose monohydrate were stored for six weeks at 40°C and 75% RH, the mixture containing anhydrous lactose showed greater moisture uptake and drug degradation. Studies have also shown that in blends of roxifiban acetate (DMP-754) and lactose anhydrous, the presence of lactose anhydrous accelerated the hydrolysis of the ester and amidine groups. Lactose anhydrous is a reducing sugar with the potential to interact with primary and secondary amines (Maillard reaction) when stored under conditions of high humidity for extended periods.

Regulatory Status

GRAS listed. Included in the FDA Inactive Ingredients Database (IM, IV: powder for injection solution; IV and sublingual preparations; oral: capsules and tablets; powder for inhalation; vaginal). Included in nonparenteral and parenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.