Carboxymethyl sago pulp (CMSP)/pectin hydrogel beads were synthesized by calcium crosslinking and further crosslinked by electron beam irradiation to form drug carrier for colon-targeted drug. Sphere-shaped CMSP/pectin 15%/5% hydrogel beads is able to stay intact for 24 h in swelling medium at pH 7.4. It shows pH-sensitive behavior as the swelling degree increases as pH increases. Fourier transform infrared spectroscopy analysis confirmed the absence of chemical interaction between hydrogel beads and diclofenac sodium. Differential scanning calorimetric and X-ray diffraction studies indicate the amorphous nature of entrapped diclofenac sodium. The drug encapsulation efficiency is up to about 50%. Less than 9% of drug has been released at pH 1.2 and the hydrogel beads sustain the drug release at pH 7.4 over 30 h. This shows the potential of CMSP/pectin hydrogel beads as carrier for colon-targeted drug.

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Carboxymethyl sag o pulp (CMSP)/carboxymethyl sago starch (CMSS) hydrogel was synthesized by electron beam irradiation. In the series of hydrogels prepared, 40%/20% CMSP/CMSS hydrogel had the highest gel fraction. The swelling capacity of CMSP/CMSS hydrogel was found to be highest in distilled water, followed by pH 11, pH 7.4, and pH 1.2. Scanning Electron Microscope photographs revealed that the drug-loaded hydrogel had a smoother surface than unloaded hydrogel. Fourier Transform Infrared and Differential Scanning Calorimetry analysis showed the absence of interaction between the hydrogels and the drug. All drugloaded hydrogels had drug encapsulation efficiency between 63% and 69%. CMSP/CMSS hydrogel swelled and allowed the release of drug at pH 7.4. These properties qualify the hydrogel as a potential candidate for controlled drug release at the ocular and colonic regions.