Enhanced drug encapsulation and extended release profiles of calcium–alginate nanoparticles by using tannic acid as a bridging cross-linking agent

Abstract

Calcium alginate nanoparticles (NPs) suffer from sub-optimal stability in bio-relevant media leading to low drug encapsulation efficiency and uncontrolled release profiles. To sort out these drawbacks, a novel approach is proposed herein based on introducing tannic acid into these NPs to act as a bridging cross-linking aid agent. Calcium–alginate NPs were prepared by the ionotropic gelation method and loaded with diltiazem hydrochloride as a model drug. These NPs were characterized in terms of particle size, zeta potential, and morphology, and results were explained in accordance with Fourier-transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The incorporation of tannic acid led to more than four folds increase in drug encapsulation efficiency (i.e. from 15.3% to 69.5%) and reduced burst drug release from 44% to around 10% within the first 30 min. These findings suggest the possibility of improving the properties of Ca–alginate NPs by incorporating cross-linking aid agents under mild conditions.

• Alginate nanoparticles
• controlled release
• diltiazem hydrochloride
• tannic acid

Acknowledgements

The authors thank the Deanship of Academic Research (DAR) at The University of Jordan for financial support. The authors also acknowledge the technical help of Miss Ayat Alhomsi. Thanks also go to Prof. Suhair Saleh and Dr Nizar Al-Zoubi (Faculty of Pharmacy – Applied Science Private University) for providing Zetasizer for some DLS measurements.

Declaration of interest

The authors report no declarations of interest.