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Octadecyltrichlorosilane Incorporated Alginate Micro-granules as Sustained-Release Carriers for Small Hydrophilic Molecules

[ Vol. 17 , Issue. 4 ]


Qing Wang and Bi-min Zhang Newby*   Pages 333 - 342 ( 10 )


Background: Hydrogels are excellent drug carriers, but their inability to retain hydrophilic drugs for a prolonged period of time has greatly limited their usage. Research has mostly focused on intricate designs and manipulations of hydrogels to expand their applications in drug delivery.

Objective: In this study, a simple approach by incorporating a hydrophobic agent, octadecyltrichlorosilane (OTS), to alginate hydrogel micro-granules (Alg-Ms), was investigated as an effective technique to prolong the release of small hydrophilic drugs.

Methods: Sodium Benzoate (SB), a highly water-soluble antimicrobial and anti-inflammatory compound, was used as a model drug. The presence of hydrophobic OTS impeded swelling of these OTS incorporated Alg-Ms (OTS-Alg-Ms), hence sustaining the release of SB.

Result: The release data was fitted with Ritger-Peppas and Peppas-Sahlin models and the results showed that SB released from OTS-Alg-Ms with higher OTS content was mainly controlled by Fickian diffusion; with a lower OTS content, OTS-Alg-Ms swelled more easily, the combined diffusion and swelling led to a faster SB release.

Conclusion: Thus, by simply tuning the OTS concentration in the solution where Alg-Ms were briefly submerged in a predefined release period, from hours to a few days, small hydrophilic drugs from these OTS-Alg-Ms could be successfully achieved.


Octadecyltrochlorosilane (OTS), alginate, hydrogels, small hydrophilic drug, sodium benzoate, polymers.


Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, 44325-3906, Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, 44325-3906

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