AN INVESTIGATION INTO THE SUITABILITY OF AMIDATED PECTIN HYDROGEL BEADS AS A DELIVERY MATRIX FOR CHLOROQUINE

The aim of the present study was to delay the release of chloroquine t o distal parts of the gastrointestinal tract by using a multiparticula te hydrogel formulation. Amidated pectin chloroquine beads (PC) with v arying pectin-to-chloroquine ratios (PC) w/w loadings of 4:1, 2.1, ant i 1:1 in the dried beads were prepared by the gelation of drug-loaded pectin solutions in the presence of calcium. In vitro release studies of chloroquine from pectin-chloroquine hydrogel beads and chloroquine diphosphate powder were carried out in simulated gastric and intestina l fluids. The total release of the entrapped chloroquine from the hydr ogel beads was achieved between 4 and 7 h in simulated intestinal flui d, but total release was not achieved in simulated gastric fluid. Howe ver, total release from chloroquine diphosphate powder was achieved by 1.5 and 2 h in gastric and intestinal fluid!;, respectively. The plas ma pharmacokinetics of chloroquine from pectin hydrogel beads and chlo roquine diphosphate solution following single or repeated dosing were compared in male Sprague-Dawley rats over a period of 60 h. Oral admin istration of the hyrogel beads to rats produced maximum plasma concent rations by 7 h, but highest plasma concentrations following chloroquin e solution administration were observed by 2 h. The dissolution data a nd appearance of significant plasma concentrations of chloroquine 2 to 4 h after oral administration suggests release in duodenum, jejunum, or ileum.