Manucol is a commercial name, so the question is really asking which pharmaceutical excipient hides behind that brand.
- Sodium alginate: This is the water-soluble sodium salt of alginic acid, obtained from brown algae, and Manucol is one of its well known commercial names, used across tablet and topical formulations as a gelling and thickening agent.
- Alginic acid: The free acid form of the same polysaccharide, but it is poorly water-soluble and is sold under its own separate trade names, not as Manucol.
- Carbopol: A man-made acrylic acid polymer with no seaweed origin at all, used for its own gelling properties but never marketed as Manucol.
- Guargum: A plant-seed polysaccharide from guar beans, chemically and botanically distinct from alginates, and again not connected to the Manucol name.
Only the sodium salt of alginic acid is sold commercially under the Manucol brand.
So the correct answer is Sodium alginate.