Page 57 - controlled drug delievery
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Types of Gastric retentive D.S.
• High density systems.
• Floating systems.
• Expandable systems.
• Bio/Mucoadhesive systems
1- High density systems
– Dosage forms with densities > 2.5 gm/cm3 will sink to the bottom of the
stomach, specially pellets may get trapped within the folds of the gastric
walls thus escaping housekeeping waves of gastric emptying.
– Commonly used excipients: barium sulphate, zinc oxide, titanium dioxide
