Lactose occurs as white to off-white crystalline particles or powder.
It is odorless and slightly sweet-tasting. Spray-dried directcompression
grades of lactose are generally composed of 80–90%
specially prepared pure a-lactose monohydrate along with 10–20%
of amorphous lactose.
alpha-D-Lactose monohydrate is used as a carrier and stabiliser of aromas, pharmaceutical products, Food industry.
A sugar that occurs in many
plants. It is extracted commercially from sugar cane and sugar beet. Sucrose is a disaccharide formed from a glucose unit and
a fructose unit. It is hydrolyzed to a mixture of fructose and glucose by the enzyme
invertase. Since this mixture has a different
optical rotation (levorotatory) than the
original sucrose, the mixture is called invert sugar.
A suspension of a-lactose monohydrate crystals in a lactose solution
is atomized and dried in a spray drier. Approximately 10–20%
of the total amount of lactose is in solution and the remaining
80–90% is present in the crystalline form. The spray-drying process
predominantly produces spherical particles. The compactibility of
the material and its flow characteristics are a function of the
primary particle size of the lactose monohydrate and the amount of
amorphous lactose.
Pharmaceutical Applications
Spray-dried lactose is widely used as a binder, filler-binder, and flow
aid in direct compression tableting.
alpha-Lactose is the primary sugar present in milk and the main energy source to a newborn mammalian through its mother′s milk. It is digested by the intestinal lactase (EC 3.2.1.108), an enzyme expressed in newborns. The enzyme′s activity declines following weaning which can lead to lactose intolerance in adult mammals.
Lactose is widely used in pharmaceutical formulations as a diluent
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 enzyme
lactase.
Spray-dried lactose should be stored in a well-closed container in a
cool, dry place.
Lactose is a reducing sugar. The amorphous lactose, which is the
most reactive form of lactose present in spray-dried lactose, will
interact more readily than conventional crystalline grades.
Typical reactions include the Maillard reaction with either
primary or secondary amines.
