Disintegrants are substances that help tablets break apart (disintegrate) into smaller particles after administration, facilitating the release and absorption of the active ingredient in the body.
Significance
Drug Bioavailability: Effective disintegration is critical for quick release and hence prompt onset of action.
Efficient Dosage Form: Ensures consistent and reliable performance of solid oral dosage forms.

Examples & Uses
Starch (corn, potato, rice): Swells upon contact with water, causing tablet disintegration.
Isapghula husk (Plantago ovata): Exhibits excellent swelling properties, promoting rapid disintegration.
Agar agar (from seaweeds): Used as a disintegrant due to swelling action.