Intragastric Distribution of Ion-exchange Resins: a Drug Delivery System for the Topical Treatment of the Gastric Mucosa

Abstract

Previous studies by this group on freeze-dried oral dosage forms containing finely-divided ion-exchange resins revealed prolonged gastric residence and uniform distribution within the stomach. The present study was carried out to ascertain whether this was due to freeze-drying, properties of the radiolabelled ionic exchange resin, or the small dosing volume used. 99mTc-labelled cholestyramine resin was administered in two dosage forms, a freeze-dried tablet which dissolved in the oral cavity (orally dissolving tablet; ODT) and a 1.5 mL aqueous suspension. Two resin particle sizes (20-40 and 90-125 microns) were studied. Oesophageal transit and intragastric distribution and residence were followed by gamma scintigraphy. In a second study, in six subjects, gastric emptying of the water-soluble fraction of the ODT and 1.5 mL of water, was measured using 99mTc diethylenetriaminepentaacetic acid. Oesophageal transit of a water-soluble marker and resin in suspension was rapid, but the transit of the resin in the ODTs was significantly prolonged. Regardless of particle size or dosage form, the resin was evenly distributed throughout the stomach with 20-25% remaining for 5.5 h. In contrast, the water-soluble marker cleared from the stomach rapidly from both dosage forms. We suggest that oral dose forms containing finely-divided ion-exchange resins may form a useful system for topical treatment of the gastric mucosa, for example in targeting to Helicobacter pylori infection.

Conventional and Novel Pharmaceutical Dosage Forms on Prevention of Gastric Ulcers

“…DA-6034 EFMS tablets showed enhanced gastroprotective effects in gastric ulcerinduced beagle dogs, indicating the therapeutic potential of EFMS tablets for the treatment of gastritis (158). In another example, it was found that in normal volunteers ionexchange resins achieved excellent distribution in the gastric cavity and had a prolonged gastric residence time, 20-25% remaining for 5.5 h. (155). More recent results by the same group indicate that the mechanism by which resin particles adhere to the mucosa is unlikely to be chargebased, since they persist in the stomach regardless of whether they bear a non-adhesive polymer coating and regardless of whether the stomach contains food (156).…”

Formulation and evaluation of Gastro-retentive drug delivery system using Fenugreek gum as novel matrixing agent

“…Gastro-retentive DDSs exhibiting controlled drug release are significantly important for drugs which are: Acting locally in the stomach (e.g. antibiotics against Helicobacter Pylori, antacids and misoprostol) [15][16][17][18][19].Absorbed incompletely due to a relatively narrow window of absorption in the GIT, such as cyclosporin, ciprofloxacin, furosemide, L-DOPA, p-aminobenzoic acid and riboflavin [3,[20][21][22][23][24][25].Unstable in the intestinal or colonic environment such as captopril [26] or exhibit low solubility at high pH values such as verapamil HCl, diazepam and chlordiazepoxide [27][28][29][30]. Polymers are principle excipient in pharmaceutical dosage forms especially with modified release.…”

Sustained delivery of propranolol by using multiparticulate gastroretentive drug delivery system

“…Gastroretentive 3 . For such an effect, the particles will need to be small from a mechanical consideration and of low density so that they might be able to float 3 .…”

“…For such an effect, the particles will need to be small from a mechanical consideration and of low density so that they might be able to float 3 . Several approaches like floating multiparticulates system using ion exchange resin loaded with bicarbonate 4 , floating beads of riboflavin using sodium alginate solution containing CaCO 3 or NaHCO 3 as gas generating agents 5 , piroxicam in hollow polycarbonate (PC) micro spheres 6 , hollow microspheres (microballoons) loaded with either Translit or Ibuprofen in an outer enteric acrylic polymer 7 , air compartment multiple-unit system for prolonged gastric residence 8 , microspheres by core solubilization technique 9 , wax and fat embedded floating micro spheres of ibuprofen 10 , floating microspheres by different solvent evaporation technique 11 , floating-bioadhesive microspheres containing acetohydroxamic acid by quasi-emulsion solvent diffusion method 12 were developed and studied for there gastroretentive properties.…”