• Mohy Eldin Ms. University of Jeddah
  • Omer Am. Polymer Materials Research Department, Advanced Technology and New Materials Research Institute, City for Scientific Research and Technological Applications, Alexandria, Egypt
  • Wassel Ma. AL-Azhar University
  • Tamer Tm. Advanced Technology and New Materials Research Institute
  • Abd Elmonem Ms. National Organizations for Drug Control and Research
  • Ibrahim Sa. National Organizations for Drug Control and Research


Objective: The main objective of this study is to evaluate the swelling behavior of pH sensitive chitosan (CS) grafted alginate (ALG) hydrogel microcapsules and compared with a simple alginate-chitosan mixed polyelectrolyte complex (PEC) to show the benefits of the used covalently grafting technique. In addition, the behavior of the swelling process under physiological conditions to stimulate gastric, colonic and intestinal medium for grafted PEC microcapsules will be investigated as well.

Methods: The new pH sensitive hydrogel microcapsules were prepared using “grafting to†technique. Swelling studies were conducted in buffer saline solutions with different pHs using wet beads. In addition; the sensitivity of the grafted microcapsules to the change of pH in the simulated gastric fluid (SGF; pH 1.2), (SIF; pH 6.8) and (SCF; pH 7.4) was investigated.

Results: It was observed from the swelling studies that sharp phase transition was recognized between pH 3–4. While this transition became broader and recognized between pH 3.0-7.4, where the maximum value of the equilibrium swelling degree was varied depending on the variation of CS concentration from 0.1% to 0.5%, both grafted and mixed microcapsules exhibit higher swelling degree at high pH 6.8 (120%, 100%) respectively.

Conclusion: It was clear from all swelling studies that the grafting technique may be a suitable way for large-scale production of pH sensitive alginate–chitosan microcapsules as a potential system for site-specific oral delivery of protein drugs to different regions of the intestinal tract.


Keywords: Alginate, Chitosan, Hydrogel, Grafting, pH Sensitive, Swelling


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How to Cite
Ms., M. E., O. Am., W. Ma., T. Tm., A. E. Ms., and I. Sa. “NOVEL SMART PH SENSITIVE CHITOSAN GRAFTED ALGINATE HYDROGEL MICROCAPSULES FOR ORAL PROTEIN DELIVERY: II. EVALUATION OF THE SWELLING BEHAVIOR”. International Journal of Pharmacy and Pharmaceutical Sciences, Vol. 7, no. 11, Aug. 2015, pp. 331-7,
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