In vivo evaluation of a novel gastric retentive formulation based on ion exchange resins

• Published in: Journal of controlled release Vol. 42; no. 2; pp. 105 - 113
• Main Authors: Atyabi, F., Sharma, H.L., Mohammad, H.A.H., Fell, J.T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.1996; Elsevier
• Subjects: Biological and medical sciences; Coating; Floating system; Gastric emptying; General pharmacology; Ion exchange resins; Medical sciences; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Gastric emptying; Ion exchange resins; Coating; Floating system; Human; Stomach; Semipermeable membrane; Microsphere; Pharmaceutical technology; Buoyancy; Oral administration; Normal; Retention; Hydrogencarbonates; Dosage form; Pharmacokinetics; Ion exchange resin
• ISSN: 0168-3659; 1873-4995
• DOI: 10.1016/0168-3659(96)01344-2

Systems that exhibit gastric retention are of value in several areas of therapy. A novel floating system based on ion exchange resins has been investigated and evaluated in vivo. The method relies on ion exchange resins loaded with bicarbonate, which, on contact with media containing hydrochloric acid, release carbon dioxide causing the resin to float. Extension of the floating time is achieved by coating the bicarbonate loaded resin particles with a semipermeable membrane. Two resins were investigated and both exhibited in vitro floating times of over 24 h using a standardised procedure. Studies in human volunteers were carried out using gamma scintigraphy. The coated resins were compared to an uncoated control in subjects receiving a light breakfast. The coated resin based on Dowex 2 × 10 showed significantly prolonged residence times ( P < 0.002) over the non-coated control when compared at 60 and 150 min using a modified gastric emptying index.