pH-sensitive magnetic microcapsules for simultaneously controlled-releasing two drugs

Abstract

pH-sensitive magnetic dual drug-loaded microcapsules (MDDM) embracing magnetic nanoparticles Fe₃O₄@SiO₂ and two drugs (roxithromycin (ROX) and theophylline (TH)) were prepared through self-assembly, with methylcellulose and alginate sodium as the wall materials. MDDM was characterized with FTIR, XRD, TGA, vibrating sample magnetometer. The amount of Fe₃O₄@SiO₂ affected the drug encapsulation efficiency lightly whereas affected the diameter of MDDM obviously. The drug loading of ROX and TH was 6.44% and 7.70% at the optimized conditions, respectively. The drug releasing of MDDM expressed obvious pH-sensitivity and increased with the pH value of the medium. The total cumulative release of ROX and TH in the simulative body fluid (pH 7.4) was 83.16% and 81.86% after 12 h, while was 24.54%, 21.21% in simulative gastric liquid. MDDM had higher antibacterial activity and lower cytotoxicity than the pure drugs with same amount, showing good capability on drug protection, controlled-releasing and toxicity elimination.

Graphical Abstract

Keywords:

• Drug controlled releasing
• magnetic microcapsules
• pH-sensitive
• ROX
• TH

Acknowledgments

The authors appreciate the financial support from Young Talents' Science and Technology Innovation Project of Hainan Association for Science and Technology (QCXM202030), Hainan Provincial Natural Science Foundation of China (520QN224) and the Key Laboratory of Water Pollution Treatment and Resource Reuse of Hainan Province.

Disclosure statement

The authors declare that there is no conflict of interest.