title: Echo-planar magnetic resonance imaging of Gaviscon alginate rafts in-vivo.
abstract: Liquid Gaviscon and Gaviscon Advance are established reflux suppressant formulations. This study describes the use of echo-planar magnetic resonance imaging (EPI) to visualise non-invasively intragastric alginate rafts of Liquid Gaviscon and Gaviscon Advance in healthy subjects. Secondly, the feasibility of using relaxation rate (T2(-1)) measurements to monitor changes in the physicochemical properties of the rafts in-vivo is evaluated. Six subjects ingested 500 mL of a liquid meal and received a single dose of 20 mL Liquid Gaviscon or 10 mL Gaviscon Advance on 2 separate visits each and were imaged every 15 min. An alginate raft was observed in the stomach for all subjects and both treatments. The raft was observed to consist of a few large fragments on the majority of the scans for both products. At t = 60 min a raft was still present in all cases. Three-dimensional volume reconstructions showed, for the first time, the spatial distribution of the rafts within the gastric lumen. The T2(-1) data showed potential for assessment of dynamic changes in the physicochemical properties of the alginate rafts in-vivo. We conclude that EPI shows great potential in assessing alginate rafts formation in-vivo.
authors.affiliation: Magnetic Resonance Centre, School of Physics and Astronomy, Nottingham NG7 2RD, UK.
authors.forename: Luca
authors.initials: L
authors.lastname: Marciani
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Little
authors.forename: Janice
authors.initials: J
authors.lastname: Snee
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Coleman
authors.forename: Damian J
authors.initials: DJ
authors.lastname: Tyler
authors.forename: John
authors.initials: J
authors.lastname: Sykes
authors.forename: Ian G
authors.initials: IG
authors.lastname: Jolliffe
authors.forename: Peter W
authors.initials: PW
authors.lastname: Dettmar
authors.forename: Robin C
authors.initials: RC
authors.lastname: Spiller
authors.forename: Penny A
authors.initials: PA
authors.lastname: Gowland
mesh_terms: D000328:Adult; D000464:Alginates; D000536:Aluminum Hydroxide; D000863:Antacids; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003287:Contrast Media; D004338:Drug Combinations; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D012824:Silicic Acid; D017693:Sodium Bicarbonate; D013997:Time Factors
chemical_list: D000464:Alginates; D000863:Antacids; D003287:Contrast Media; D004338:Drug Combinations; D012824:Silicic Acid; D000536:Aluminum Hydroxide; C007829:alginate, aluminium hydroxide, magnesium trisilicate, sodium bicarbonate drug combination; D017693:Sodium Bicarbonate