Floating-bioadhesive gastroretentive Caesalpinia pulcherrima-based beads of amoxicillin trihydrate for Helicobacter pylori eradication

Abstract

Context: An oral dosage form containing floating bioadhesive gastroretentive microspheres forms a stomach-specific drug delivery system for the treatment of Helicobacter pylori.

Objectives: To prepare and evaluate controlled release floating bioadhesive gastroretentive chitosan-coated amoxicillin trihydrate-loaded Caesalpinia pulcherrima galactomannan (CPG)-alginate beads (CCA-CPG-A), for H. pylori eradication.

Materials and methods: CCA-CPG-A beads were prepared by ionotropic gelation, using 2(3) factorial design with quantity of drug, combination of CPG with sodium alginate and concentration of calcium chloride as variables. Beads facilitated mucoadhesion to gastric mucosa with floating nature caused by chitosan coating for wide distribution throughout GIT. Developed beads were evaluated for characteristics like beads size-morphology, entrapment efficiency, DSC, XRD, FTIR, swelling ratio, in vitro mucoadhesion, in vitro drug release, in vitro floating and in vitro H. pylori growth inhibition studies. CCA-CPG-A beads were studied in Wistar rats for in vivo gastric mucoadhesion, in vivo H. pylori growth inhibition studies using PCR amplification of isolated DNA, rapid urease test.

Result: Developed beads possess drug release of 79-92%, entrapment efficiency of 65-89%, mucoadhesion of 61-89%. In vivo mucoadhesion study showed more than 85% mucoadhesion of beads even after 7th hour. In vitro-in vivo growth inhibition study showed complete eradication of H. pylori.

Discussion: CPG-alginate and chitosan in beads interacts with gastric mucosubstrate surface for prolonged gastric residence with floating bioadhesion mechanism for H. pylori eradication in rats.

Conclusion: Floating bioadhesive CCA-CPG-A beads offer a promising drug delivery system for H. pylori eradication at lower dose, reduced adverse effect and enhance bioavailability.

Keywords: Amoxicillin trihydrate; Helicobacter pylori; beads Caesalpinia pulcherrima galactomannan; gastroretentive.