Preparation and evaluation of polymeric beads composed of Chitosan–Gellan Gum–Gum Ghatti/-Gum Karaya polyelectrolyte complexes as polymeric carrier for enteric sustained delivery of Diclofenac sodium

Abstract

Abstract Background An enteric coating is a multistep technique that involves deposition of a polymeric barrier over uncoated orally administered tablets to prevent them from dissolving or disintegrating in the stomach. However, as soon as the coating dissolves in the alkaline environment of intestine, the whole of the drug come in direct contact with gastric mucosa leading to irritation to distal parts of the gastrointestinal tract (GIT). Considering the above facts, there is clear need to develop a simple and effective enteric release formulation for gastric irritant drugs like Diclofenac sodium (DS). The goal of this study was to create enteric release polymeric polyelectrolyte complex (PEC) beads made up of cationic Chitosan (CH) and anionic Gellan Gum (GG) for sustained DS delivery to the intestine. The beads were prepared by extruding a solution of GG and Gum Ghatti (GT) or GG and Gum Karaya (GK) bearing DS into CH solution in 1% w/v acetic acid, with the help of a syringe fitted with a 18 gauge hypodermic needle. Results Instantly created spherical beads were dried in a hot air oven 60 °C overnight. In 0.1 M HCl and 6.8 pH phosphate buffer, the dried beads were tested for drug entrapment in the beads, in vitro swelling of beads and in vitro drug release studies from the beads. The % drug entrapment efficiencies (% DEE) of these PEC beads ranged from 59.54 ± 2.09 to 81.03 ± 4.22%. In 0.1 M HCl, the PEC beads swelled the least in vitro, but expanded significantly in phosphate buffer (pH 6.8). The in vitro release of Diclofenac sodium from different PEC beads in 0.1 M HCl was found to be less than 7.5 percent, whereas the release was sustained for 6 h in phosphate buffer (pH 6.8). Conclusions From the experimental data, it may be concluded that these PEC beads can be useful as potential multiple-unit enteric release polymeric carrier systems for sustained delivery of gastric irritant drugs like Diclofenac sodium.

Keywords

• Chitosan
• Gum Ghatti
• Gum Karaya
• Gellan Gum
• Polyelectrolyte complex
• Drug release