Macrogol as Excipient

Polyethylene glycol (PEG), as pharmaceutical substance well known under the name Macrogol, is used as an osmotic-type laxative to treat constipation or to clear the colon before coloscopy.

Polyethylene glycols are polymers of ethylene oxide with the following chemical structure: HOCH2-[CH2-CH2 -O]n-CH2OH (n: average number of EO-units). Within the pharmaceutical industry the number included in the names of polyethylene glycols indicates the average molecular weight.

PEGs with a molecular weight up to 400 are non-volatile, clear, viscous, colourless or almost colourless hygroscopic liquids at 25C. They are used as drops, parenterals and fillings for gelatin capsules.

Polyethylene glycols with a molecular weight above 3000 are white or almost white solids with a waxy or paraffin like appearance and available as powder. They are used as ointment bases, tablet bindings, film coatings and lubricants.

Macrogol 3350 & Macrogol 4000, widely used as active ingredients, have the ability to bind a defined amount of water, which is transmitted immediately into the large intestine. There it softens the stool and increases the stool volume, which leads to a stimulation of intestinal peristalsis and increases the number of bowel movements.