Preparation of pH-sensitive beads for NSAID using three-component gel systems

Zsófia Fenyvesi, Alíz Auner, Dirk Schmalz, Eszter Pásztor, Gabriella Csóka, Klára Gyires, Sylvia Marton, Imre Klebovich, István Antal

Research output: Contribution to journalArticle

8 Citations (Scopus)


The aim of this study is to prepare novel pH-sensitive beads to obtain a gastric mucosa protective formulation and to ensure drug delivery into the intestine. Diclofenac sodium was used as a model drug. Bead formation was achieved by ionotropic gelation method using three-component gel system containing sodium alginate (Na-Alg), hydroxyethylcellulose (HEC) and hydroxypropylmethylcellulose (HPMC). Factors influencing the characteristics of beads (exposure time, cross-linking agent concentration, polymer ratio) were investigated by swelling and erosion tests based on gravimetric method. Drug release was tested in distilled water and/or artificial digestive fluids and evaluated with Korsmeyer-Peppas equation and Baker-Lonsdale model. The encapsulation behaviour was qualitatively indicated by differential scanning calorimetry (DSC) method. In vivo experiments were conducted to test ulcerogenicity and intestinal absorption in rats. HPMC increased the encapsulation efficiency (EE) and HEC improved the drug release in the intestinal fluids. The equilibrium water uptake (EWU) was correlated with exposure time, calcium chloride concentration and HEC amounts. Bead erosion increased proportionately to exposure time, while it reduced when calcium chloride concentrations were increased. Higher amounts of HEC increased, while higher pH values reduced the encapsulation efficacy. The in vivo experiments demonstrated that the studied encapsulation technology markedly reduced the ulcerogenic effect of diclofenac.

Original languageEnglish
Pages (from-to)4285-4295
Number of pages11
JournalJournal of pharmaceutical sciences
Issue number11
Publication statusPublished - Nov 2009


  • Alginate
  • Biodegradable polymers
  • Controlled release
  • Diclofenac sodium
  • Gastric ulcer
  • In situ gelation
  • Intestinal absorption
  • Microparticles
  • Oral drug delivery
  • pH-sensitive beads

ASJC Scopus subject areas

  • Pharmaceutical Science

Fingerprint Dive into the research topics of 'Preparation of pH-sensitive beads for NSAID using three-component gel systems'. Together they form a unique fingerprint.

  • Cite this