الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
In this work, sustained release metformin hydrochloride formulations was prepared aiming to control the release of MET over time, allowing the dose to be absorbed slowly and lowering its dosing frequency.This was achieved by modulation of water solubility of MET via hydrophobic ion-pairing (HIP) technique, where cationic MET was paired with different anionic ligands (Carbopol (CB), sodium dodecyl sulphate (SDS) or tannic acid (TA)) to form more hydrophobic MET complexes. These complexes were characterized, then Carbopol/MET (CB/MET) complex of charge ratio 2:1 was selected for further loading into calcium alginate beads as a mucoadhesive carrier for sustained oral delivery of MET. The release of MET from different complexes and from CB/MET complex-loaded alginate beads in simulated gastric (SGF) and simulated intestinal fluid (SIF) were examined. CB/MET complex-loaded beads achieved sustained release of MET superior to that of other formulations. When tested for their efficacy in vivo, using diabetic rats, complex-loaded beads resulted in a superior antidiabetic effect to that of commercial extended release tablets (Glucophage® XR 1000). This in-vivo efficacy was attributed to the sustained release profile and the mucoadhesive effect of alginate beads (as shown via an independent experiment). Moreover, pathophysiological examination of intestinal tissues showed that the beads were biocompatible.